Datapack Folder Outside of World/Save Folder

There should be a specific folder for data packs outside of the world/save folders. This should be in the same spot as the resource pack folder, under %appdata%. That way, data packs don't have to be copied from world to world, and you don't risk losing them if the world is erased.

I understand that, unlike resource packs, people may not want their data packs to go from world to world. But I would just suggest having them disabled by default, the same as any other experimental features. When a world is created, you can go to a specific "Data Packs" button and enable them, along with "Villager Trade Rebalance" if you want. Or, they can be enabled in-world via the /datapack command.