decentralized social media

I posted this as a reply to a video. I'm reposting it here because I really want to know the answer to my question:

Decentralized social media is a great concept, but what I don't understand, and what no one has been able to explain to me is how it's sustainable. What I mean by that is who's paying for it. Cryptocurrency is fine but it still has to translate to fiat currencies because it's going to be sometime before cryptocurrencies are widely accepted as payment in the real world.

Someone (yes I know multiple people) is running the servers, someone is paying money to run those servers, sooner or later those people running the servers are going to want to see payback on their investment.

How exactly are these people going to get paid for the servers that they're running?