>>30888037It is officially called the "Black Clover". It's basically a rotation system for the main games to prevent you from using transfer-only moves in the new metagame.
The main benefit of this system is that it means people don't need to transfer something from some completely legit Gen 3 event or Gale of Darkness or something in order to be completely competitive in the current metagame. Basically, it's a way to mitigate the advantage turbo-autists who reset entire games for specific Pokémon/moves might have.
The main shortcoming, of course, is that Pokémon need to be rebred in new generations regardless of whether or not they actually change significantly.
>>30889282Power creep in the TCG exists primarily for the sake of giving people a reason to actually buy new cards. There's no point in buying new sets if all the good cards are in older ones. Therefore, one of two things happens: either power creep is used to make new cards get continuously stronger than old ones, or rotations are used to ensure new ones eventually get a chance to shine as older ones that outclass them are banned from common use.
This generally doesn't apply to the main game very much, though, since the amount of actual 'rotation' is very temporary and extremely limited.
