This Datapack was made for my private Minecraft server but it is an essential vanilla+ pack for any world or server.

Structures:

Two new structures: The witches gathering for swamp biomes, and the pillager camp for mega taigas.
Tweaked pillager outpost tower and added vindicator on the top floor.
Trail Ruins now spawn in savannas and sparse jungles ontop of the original biomes.
Removed beetroot seeds from end city loot chests, and added iron/daimond enchanted axes and golden apples.
Tweaked and rebalanced loot tables for suspicious sand/gravel in the following structures: Desert well, cold and warm Ocean Ruins, and Trail Ruins.
Removed tridents from one of the trail chambers loot tables.
Added spyglass to shipwreck map chest loot table.

Recipes:

New dye recipes: Coal and charcoal can be crafted into black dye, resin clumps can be crafted into orange dye, turtle scute can be crafted into green dye, blue and yellow dye can be crafted into green dye, and armadillo scute can be crafted into brown dye.
Red sand, red sandstone, and smooth red sandstone can now be crafted with red dye.
Cut copper blocks can be uncrafted into copper ingots.
Chiseled copper, copper doors, copper trap doors, copper grates, copper chests, and lighting rods can now be smelted down into copper ingots.
Copper chains and copper bars can now be smelted into copper nuggets.
Iron doors, iron trapdoors, minecarts, cauldrons, and hoppers can now be smelted into iron ingots.
Chains, buckets, shears, heavy weighted pressure plates, and iron bars can now be smelted into iron nuggets.
Light weighted pressure plates can be smelted into gold nuggets.
Golden horse armor, copper horse armor, iron horse armor, golden nautilus armor, copper nautilus armor, and iron nautilus armor can now be smelted into a full ingot instead of just a nugget.
Pistons, droppers, dispensors, levers, and observers can be crafted with blackstone and deepslate.
Wool can be crafted into string.
Completely remade deepslate recipes. Polished deepslate and all blocks made from polished deepslate now craft with normal deepslate instead of cobbled deepslate.
The recipe for nether brick fences now matches the other fence recipes.
Amethyst shards can be crafted from amethyst block, amethyst cluster, and all amethyst buds.
Added recipes for smelting cobblestone slabs and stairs into stone slabs and stairs.
Added a couple of missing stonecutter recipes for chiseled blackstone and deepslate.

Tweaks and Small Additions:

New advancement for killing a blaze with a snowball.
Powered Rails and gold nuggets now distract piglins, and powered rails, bells, and light weighted pressure plates now anger piglins when broken.
Many items classified as tools can now be enchanted with curse of vanishing.
Mining stone slabs and stone stairs without silk touch now drops cobblestone slabs or stairs.

Realms Reborn Data Pack