Sites need to understand that. No one wants to pay 10$/month for some premium crap, all we want is to replace ad revenue.

But sadly most of them charge ridiculous amounts, so it's infeasible to support many of them. People end up choosing the big ones because they provide the most value per money, so we get more monopolization.

The point is that it is not one dollar, actual server costs may still grow, so subscrptions for social media are still not enough to support the infrastructure behind. Look at twitter, the subscription is there (they call it $8chan now lol) but it still costs a lot of money. The question is whether giant social media sties can be as profitable as other non-tech companies, and it's a valid question.