To be fair, most game developers are just now figuring out this whole crypto world. The people that are knowledgeable in crypto are learning game development because they have an idea. I don't believe the two worlds have fully collided yet.
I have ads. Personally how I would monetize it is introduce the dreaded microtransactions that help your progress. Perhaps a "premium tier". Also have in the terms of services that a percentage like .01% of your processing power will go into a mining pool to help the developers. Crypto faucets have been doing that for years. But you still can't make money until you create a game that people want to play.
It is a though balance, true, but at least in theory I think is possible to make a great game that fairly rewards both users and developers, the first to do such a game (and it doesn't need to be complex, just look at flappy bird or candy crush) would become rich.