Major content :
Ars Nouvea - A magic mod that allows players to craft their own spell, create magical artifacts, perform rituals , and much more. Build a spell to fit your needs, create powerful baubles and trinkets. Automate your base with magical servents, and power magical machines. The sky's the limit ;)
Create - Create adds automation and tech on a scale I've never seen before, its a side of the modding community that isn't talked about often. If you want full brick blocks without having to scour in a river for hours to help build an Amazon fulfillment center. Then ...
Make a infinite cobblestone generator with working drills on the side, which feeds into an item vault, pulling from that is a funnel that is connected to conveyors to grinders that, you gussesd it, grind it down to gravel. The gravel then goes through a different set of grinders to turn it into sand. Sand gets delivered to a "washing station", working fans blowing water on passing objects, which has a high chance of producing clay balls. That is then delivered to a "cooking station", working fans blowing fire on passing objects, to turn stacks of clay into bricks. Those bricks can be compressed into full blocks.
You can have that running at home while you can do whatever... like flying.
Create: Areonautics adds physics to Minecraft, doesn't sound like a lot but it is a game changer. Most mods adding anything flying would just be a craftable plane/helicopter/etc. This mod can make anything you create an actual physics object that can move throught the world via propellers, steam, engines, hot air ballons, etc. I didn't want to rely on teleporting and waystones to get throughout the world, now you can create a plane, a flying house, a Jeep, a train, literally whatever you want.
Also quality of life mods like Farmer's delight, Yung's redesigning of structures, Relics adds amulets and rings that add passive buffs, RPG you get warrior, rogue, and archer playstyles. Legendary weapons with crazy effects, also planning to add pet mods and a couple other things :p