"How to pay" always seemed like the easy half of the problem to solve, "how to manage what should be paid" seems much harder as nobody wants to deal with sorting through fraction of a penny payment approvals. Is 0.01 cent per game acceptable? 0.05? If you accept at 0.01 and it goes to 0.05 do you have to re-accept? If everyone decides sets 0.1 cents as an auto-approve boundary does that mean every site is now going to try to charge 0.0999 cents? Does some centralized entity try to set these rates instead? How does the system protect against the equivalent of collect call scams? Does it protect against that in a way that doesn't limit actually using a service very quickly?

It's like the permissions problem (really easy to prompt, really annoying to do so, really really bad to just assume yes or no all the time) except worse.

In regards to distributed serving using the client endpoints it has a strong tendency to be more work, less reliable, and not as scalable (see peertube). What has seemed to work is offloading as much of the functionality for that user as you possibly can to that user's device. E.g. want to play a game against the computer? Run the chess engine WASM bundle on your device instead of the server (lichess does this).