I totally agree this payment pattern would work. I think the technical implementation is pretty straightforward but getting enough writers and artists to join would be difficult.
Not really. Everyone is paying monthly anyways it can just be a part of that or a surcharge on top. And I don't envision this being a mastodon thing but a "serious writing/news/art" kind of thing. Alteady there is a lot more asking of direct support online than twenty years ago. KoFi, medium subscriptions etc. I think people are open to the idea of direct sponsorship of creative people they like. The product space is there we just need good infra.