More supply does not automatically mean the best games rise to the top. The way storefronts like iOS and Steam work is there's really weak categorization and 'top seller' lists and maybe tagging and... that's it. There are no mechanisms in place to find the 'best games' and make them rise to the top; no heavy user rating rankings, no time played rankings, no rankings based on which games your friends play, etc.

This is part of why he points out the huge increase in Steam launches. Back when Steam was curated, the front page changed infrequently and you could count on at least half the games up there being worth a glance (even if they weren't worth buying). Now there's basically no filter and half the games that go up are early access or perpetual betas or games from 2001.

The best games aren't rising to the top. The games that rise to the top are rising to the top. Sometimes the best games are ALSO coincidentally the ones that rise to the top, but not always.

If you want a tired example, look at Flappy Bird. It wasn't a terrible game, but it wasn't an amazing one either. It was just an adequate game, and it managed to get high enough in the charts that it stayed there, because the visibility ensured its success. Like it or not, but life is that way for many indies right now.

(For reference, I've shipped titles on Steam and in the boxed AAA game market.)