This is one of the reasons people sign up and stay — because there are no ads and the Medium isn’t selling out. In my opinion, this is fantastic. Maybe there are other ways for writers to make money, such as leverage brands to pay them for promoting their products in an article. Medium won’t curate such articles, but as long as you disclose the sponsorship — you’re good.
They need more curators for sure, especially right now. People are writing more during quarantine.