It’s used to refer to a specific category of high budget, high sales games. It’s an obvious target market.
Petitio principii. This is your opinion and a logical fallacy - it is also not an opinion I share. SomeAAA games look generic, but so do some indie games.
Of those games, only Inside is indie. Ori is backed / published by Microsoft, and Homeworld was as AAA as it gets (published by Sierra). Both Ori and Inside are much smaller production games, and Homeworld is just plain old.