People pay for lots of social gathering type places - community centers, libraries, gyms, clubs and such. But they only do so if the prices are reasonable. And prices are usually reasonable because the club in question is not trying to grow till it takes over the world. It is a roughly fixed size place, where subscription fees pay for keeping the place running.

The cost of running most social media is only about a $1/year (yes year not month) [1]. Social media companies when they want to charge $50-100/year. People are not stupid. Why would they pay more than $2/year.

[1] https://news.ycombinator.com/item?id=38291427