Imho the strength of Indie games was being able to try ideas too risky to bet AAA budget on, or to target niche audiences deemed too small to make AAA profit

Neither of these is going away. The marketing strategy of teasing your game for months or years to build a fan base is going away. But if you life by "put up or shut up" I believe there is still room to win on vision alone.

If you don't have a unique enough vision (like most AAA, visions are risky) then I agree that you have to migrate up and just outspend everyone else