By pay to play, do you mean something like classic arcades? Where players pay and they can play for a specific amount of time?
I’m not sure if that would make things better. I wouldn’t like to invest in a site that I have to keep paying to play games, I’m sure a lot users out there think the same.
My understanding of Itch, is that it gives freedom to the developers to distribute their games on their own terms. That means a developer can make a game, and sell each level individually, or sell extra levels (Like DLC). They can also offer a level or two for free. This would allow users to try a game before they buy it, and possibly buy chunks of the game at a time.
However this is the developer’s choice. If a developer doesn’t want to invest time into that, they can just provide the full game on a specific price and that’s the end of it. Indie devs don’t have resources to invest into many features.