An analogous transformation will begin to take place on open social media as well. One of the benefits that private platforms will provide is you don't have to put nearly as much work into this formalization and web of trust stuff. Your chatroom of you and 300 of your closest friends is old school.

It will of course actually be you, 300 of your closest friends and a handful of very convincing LLM bots (or so you suspect) but hey who's counting? Meanwhile things like domain names, crypto wallets, government ID, or someone with those things vouching for you will be necessary on social media.