As an indie game developer (hard to get more indie than me, I think, since I'm doing this mostly solo), I can attest that it's never been easier to get your game on Steam or a console platform. On Steam it's mostly a matter of a $100 fee and filling a form. Consoles are a bit harder, but still dramatically more open to indie titles than say a decade ago, and all of them are possible to get on even for small developers.

I also wouldn't say that "the group of indie dev studios is dwindling". It's just a matter of the old indie studios "growing up" to become bigger enterprises, but there is tons of other people replacing them on the lowest rung, with teams of several people and true labor of love projects.