What if Ability capsules were expanded to be more like TMs? E.g., there’s ACs for Static, Guts, Chlorophyll, etc. and any pokémon that’s compatible with that ability will learn it. There might need to be some “base” or “blank” capsule to get their original ability back in that system, ‘cuz we can’t be giving out Wonder Guard, Water Bubble, or Levitate ACs… maybe those pokémon will just be unable to use ACs.
I’m a little iffy on this, purely because abilities are able to define how Pokémon work much more completely than moves (usually) can. Like, you raise Pokémon with abilities that are too overpowered to give out indiscriminately, but what about the Pokémon that originally had those abilities? There’s no point in a Furfrou without Fur Coat, or a Darmanitan without Zen Mode, let alone some of the really mad stuff like a Wishiwashi without Schooling or a Shedinja without Wonder Guard. A bunch of Pokémon have abilities that don’t particularly matter or aren’t very interesting, but I’m not convinced the implementation of a TM-like system that would be basically unusable by a pretty large fraction of all Pokémon is the way to fix that.