A solid foundation of (Fabric) mods to build on. Heavy on the performance, gameplay, & interface improvements, light on the new additions. New additions are chosen specifically to shore up some of the weaknesses of vanilla Minecraft, without adding anything to the game that might interfere with other content-based mods you might want to install (no new biomes, for example).

Modlist & description:

Performance

Lithium (https://www.curseforge.com/minecraft/mc-mods/lithium) Client/server performance boost.
Phosphor (https://www.curseforge.com/minecraft/mc-mods/phosphor) Lighting performance boost.
Sodium (https://www.curseforge.com/minecraft/mc-mods/sodium) Rendering engine performance boost.
FerriteCore (https://www.curseforge.com/minecraft/mc-mods/ferritecore-fabric) Reduce memory usage.
Iris Shaders (https://irisshaders.net/) Enables shaders at a much higher framerate than Optifine.
Cull Less Leaves (https://www.curseforge.com/minecraft/mc-mods/cull-less-leaves) Cull some tree leaves from rendering, improving render speed in high-tree areas.
DashLoader (https://www.curseforge.com/minecraft/mc-mods/dashloader) Cache assets making all loads after the first much faster (the first much slower, though).
Entity Culling (https://www.curseforge.com/minecraft/mc-mods/entityculling) Cull entities that aren't visible.
Krypton (https://www.curseforge.com/minecraft/mc-mods/krypton) Improve networking performance and security.
MemoryLeakFix (https://www.curseforge.com/minecraft/mc-mods/memoryleakfix) Fixes multiple memory leaks.
Server Performance - Smooth Chunk Save (https://www.curseforge.com/minecraft/mc-mods/smooth-chunk-save) Saves chunks continuously instead of all at once, reducing server lag.

Interface/Control improvements

JEI (https://www.curseforge.com/minecraft/mc-mods/jei) Adds recipe list for crafting
JER (https://www.curseforge.com/minecraft/mc-mods/just-enough-resources-jer) JEI addon that adds mob drops, ore gen, etc.
Mouse Tweaks (https://www.curseforge.com/minecraft/mc-mods/mouse-tweaks) Improved mouse controls for crafting and inventory management
Clumps (https://www.curseforge.com/minecraft/mc-mods/clumps) XP orbs behave better.
AppleSkin (https://www.curseforge.com/minecraft/mc-mods/appleskin) Improves hunger visualization bar.
Polymorph (https://www.curseforge.com/minecraft/mc-mods/polymorph-fabric) When recipes could produce multiple outputs, choose which one you want.
Extended Armor Bars (https://www.curseforge.com/minecraft/mc-mods/fabric-extended-armor-bars-forked) Extends and improves armour bars to show your actual armour and toughness.
Amecs (https://www.curseforge.com/minecraft/mc-mods/amecs) Adds the ability to use modifiers when binding keys.
Enchantment Descriptions (https://www.curseforge.com/minecraft/mc-mods/enchantment-descriptions) Adds descriptions to the tooltip of enchanted books.
Equipment Compare (https://www.curseforge.com/minecraft/mc-mods/equipment-compare-fabric) Adds another tooltip for equipment showing what you currently have equipped, for comparison.
Farsight (https://www.curseforge.com/minecraft/mc-mods/farsight-fabric) See farther on servers that limit view distance.
Inventory HUD+ (https://www.curseforge.com/minecraft/mc-mods/inventory-hud-forge) Add configurable parts of your inventory to your HUD.
Item Highlighter (https://www.curseforge.com/minecraft/mc-mods/item-highlighter-fabric) Highlights newly-picked up items.
Item Model Fix (https://www.curseforge.com/minecraft/mc-mods/item-model-fix) Fixes weird gaps between model edges.
Jade (https://www.curseforge.com/minecraft/mc-mods/jade) Adds UI element that displays info about what you're currently looking at.
Mod Menu (https://www.curseforge.com/minecraft/mc-mods/modmenu) Adds a menu item list and configure installed mods.
Pick Up Notifier (https://www.curseforge.com/minecraft/mc-mods/pick-up-notifier) Adds UI notifications when items are picked up.
Reese's Sodium Options (https://www.curseforge.com/minecraft/mc-mods/reeses-sodium-options) More-usable options UI for Sodium.
Tool Stats (https://www.curseforge.com/minecraft/mc-mods/tool-stats) Additional tooltip stats for tools.
Xaero's Minimap (https://www.curseforge.com/minecraft/mc-mods/xaeros-minimap) Adds a minimap.
Xaero's World Map (https://www.curseforge.com/minecraft/mc-mods/xaeros-world-map) Adds a world map.
Cycler (https://www.curseforge.com/minecraft/mc-mods/slot-cycler) Easily cycle hotbar slots with other items in the same row.
TrashSlot (https://www.curseforge.com/minecraft/mc-mods/trashslot-fabric-edition) Adds a trash icon to your inventory to destroy items.
BetterF3 (https://www.curseforge.com/minecraft/mc-mods/betterf3) A more human-readable F3 screen.

Gameplay

FallingTree (https://www.curseforge.com/minecraft/mc-mods/falling-tree) Chop a single block of a tree to fell the whole tree.
CleanCut (https://www.curseforge.com/minecraft/mc-mods/cleancut) Attack enemies through sensible obstructions.
Diagonal Fences (https://www.curseforge.com/minecraft/mc-mods/diagonal-fences) Place fences on a diagonal!
Easy Anvils (https://www.curseforge.com/minecraft/mc-mods/easy-anvils) Gives anvils an inventory and improves adding enchantments.
Easy Magic (https://www.curseforge.com/minecraft/mc-mods/easy-magic) Gives enchanting tables an inventory and enchanting improvements.
Visual Workbench (https://www.curseforge.com/minecraft/mc-mods/visual-workbench) Items inserted into a crafting table stay there, and are rendered on top.
Carrier (https://www.curseforge.com/minecraft/mc-mods/carrier) Carry chests/entities/spawners in your bare hands.
Trinkets (https://www.curseforge.com/minecraft/mc-mods/trinkets) Adds extra equippable inventory slots.
Elytra Slot (https://www.curseforge.com/minecraft/mc-mods/elytra-slot-fabric) Adds an Elytra trinket slot.
Charm of Undying (https://www.curseforge.com/minecraft/mc-mods/charm-of-undying-fabric) Adds a Totem of Undying trinket slot.
Fabric Seasons (https://www.curseforge.com/minecraft/mc-mods/fabric-seasons) Adds seasons that last 28 in-game days.
LambDynamicLights (https://www.curseforge.com/minecraft/mc-mods/lambdynamiclights) Adds dynamic lighting.
NetherPortalFix (https://www.curseforge.com/minecraft/mc-mods/netherportalfix-fabric) Come back out the same portal you go in, even when portals are built close together.
RightClickHarvest (https://www.curseforge.com/minecraft/mc-mods/rightclickharvest) Harvest & replant crops with a single right-click.
You're In Grave Danger (https://www.curseforge.com/minecraft/mc-mods/youre-in-grave-danger) When you die, you leave a grave with your items in it to come back to and collect.
Block Runner (https://www.curseforge.com/minecraft/mc-mods/block-runner-forge) Move faster on certain blocks.
Better Combat (https://www.curseforge.com/minecraft/mc-mods/better-combat-by-daedelus) Revamps the melee combat system to add variety to your attacks.
Guard Villagers (https://www.curseforge.com/minecraft/mc-mods/guard-villagers-fabric) Adds guards to villages.

Additions

Nature's Compass (https://www.curseforge.com/minecraft/mc-mods/natures-compass) Adds compass that allows you to search for biomes.
Waystones (https://www.curseforge.com/minecraft/mc-mods/waystones-fabric) Adds craftable blocks that allow for fast travel.
Charm (https://svenhjol.github.io/Charm/) A variety of gentle and empowering improvements.
Comfort (https://www.curseforge.com/minecraft/mc-mods/comforts-fabric) Adds hammocks and sleeping bags. Sleep without resetting your spawn point!
Dragon Loot (https://www.curseforge.com/minecraft/mc-mods/dragonloot) Adds new armour and a new anvil craftable from new Ender Dragon loot.
Goblin Traders (https://www.curseforge.com/minecraft/mc-mods/goblin-traders-fabric) Lil' dudes that come and trade you for stuff.
End Goblin Traders (https://www.curseforge.com/minecraft/mc-mods/end-goblin-traders-fabric) Goblin Traders in The End!
Magnum Torch (https://www.curseforge.com/minecraft/mc-mods/magnum-torch-forge) Adds torches that prevent spawning in a large area.
Quartz Elevator (https://www.curseforge.com/minecraft/mc-mods/quartz-elevator) Teleport between elevators with the same x,z coordinates using jump and crouch.
Tom's Simple Storage Mod (https://www.curseforge.com/minecraft/mc-mods/toms-storage-fabric) Connect your chests together and make finding items in your base much easier.
Vein Mining (https://www.curseforge.com/minecraft/mc-mods/vein-mining-fabric) Adds an enchantment that lets you mine connected blocks at once.
Void Totem (https://www.curseforge.com/minecraft/mc-mods/voidtotem-fabric) Adds a totem that prevents you from dying in the Void in The End.
XP Storage (https://www.curseforge.com/minecraft/mc-mods/xp-storage) Adds a book that you can store your XP in.
XP Storage Trinkets (https://www.curseforge.com/minecraft/mc-mods/xp-storage-trinkets) Adds jewellery that automatically transfers gained XP into an XP book.
Traveler's Backpack (https://www.curseforge.com/minecraft/mc-mods/travelers-backpack-fabric) Adds a pretty neat backpack with a crafting table, fluid tanks, a hose, and more.
Immersive Armors (https://www.curseforge.com/minecraft/mc-mods/immersive-armors) Adds a collection of new, interesting armour to make and wear.
Simply Swords (https://www.curseforge.com/minecraft/mc-mods/simply-swords) Adds a variety of new weapon types, compatible with Better Combat.
Small Ships (https://www.curseforge.com/minecraft/mc-mods/small-ships) Adds small, sailable multiblock ships. Can be upgraded with cannons!
Easy Emerald Tools & More (https://www.curseforge.com/minecraft/mc-mods/simple-emerald-tools-fabric) Adds standard sets of armour, tools, & weapons between vanilla Iron & Diamond.
Macaw's Bridges (https://www.curseforge.com/minecraft/mc-mods/macaws-bridges) Adds decorative bridge blocks.
Artifacts (https://www.curseforge.com/minecraft/mc-mods/artifacts-fabric) Adds a variety of powerful and weird items to find while exploring.

Misc

FTB Backups 2 (https://www.curseforge.com/minecraft/mc-mods/ftb-backups-2) Backups!
Leaves Be Gone (https://www.curseforge.com/minecraft/mc-mods/leaves-be-gone) Leaves on a cut tree decay very quickly.
Sodium Extra (https://www.curseforge.com/minecraft/mc-mods/sodium-extra) Eye candy extras for Sodium.
Better Animations Collection (https://www.curseforge.com/minecraft/mc-mods/better-animations-collection) Adds some neat animations to some models.
Villager Names (https://www.curseforge.com/minecraft/mc-mods/villager-names-fabric) Villagers will be given random names.
Auditory (https://www.curseforge.com/minecraft/mc-mods/auditory) Adds a variety of unique sounds when placing blocks and using items.

Plumbing

Balm (https://www.curseforge.com/minecraft/mc-mods/balm-fabric)
AttributeFix (https://www.curseforge.com/minecraft/mc-mods/attributefix)
ThonkUtil (https://www.curseforge.com/minecraft/mc-mods/thonkutil)
Cloth Config API (https://www.curseforge.com/minecraft/mc-mods/cloth-config)
Forge Config API Port (https://www.curseforge.com/minecraft/mc-mods/forge-config-api-port-fabric)
PuzzlesLib (https://www.curseforge.com/minecraft/mc-mods/puzzles-lib)
playerAnimator (https://www.curseforge.com/minecraft/mc-mods/playeranimator)

Fundamenta