"Only speaking personally, what happened for me was that I noticed that these utopian online communities that we reinvented are not really particularly wonderful because a lot of the loudest people in such communities are really nasty people with really nasty things to say. On the other hand, the internet has proven incredibly useful for enabling people to keep up their deep high-trust relationships (usually forged offline) across longer distances and more life changes."

It's interesting that you mention this point. There was a social network designed specifically to leverage the phenomenon by limiting the number of your friends. Here it is:

https://en.wikipedia.org/wiki/Path_(social_network)

We also saw this in the Friend-to-Friend model of decentralized schemes, esp crypto- or privacy-heavy. Freenet with F2F is probably best example today that has a mature codebase.

https://freenetproject.org/about.html#philosopy

So, it might be worth seriously considering what you brought up when evaluating alternative architectures for the Internet. Probably be an overall boost for efficiency in such architectures.