You make some good points. One thing I’d add is a weighted category system, because surely enjoyment should matter more than anything else. Honestly, I’d probably change the whole system, but a weighted approach would already be a big improvement.
Another idea for supporting downloadable games could be if Itch added a way to stream them directly on the platform. I know that’s a huge ask, but it would be incredible. And if Itch never does it, maybe they'll be replaced by a platform that will.