I agree that advertising is the root of it, but some people might still pay for modern social media. They used to pay for porn, before it was available for "free" (ad supported). Some still do. I pay for YouTube to avoid the ads. I don't think I would pay for Facebook or Tiktok though. Possibly an uninformed opinion as I've never used those platforms.

The $ from people paying for subscriptions and the $$$$$$ from ad revenue, is too much of a bridge to cross.