I've been thinking in a similar space lately, about how a "parallel web" could look like.

One of my (admittedly half baked) ideas was a vouching similar with real world or physical incentives. Basically signing up requires someone vouching, similar to this one where there is actual physical interaction between the two. But I want to take it even further -- when you signup your real life details are "escrowed" in the system (somehow), and when you do something bad enough for a permaban+, you will get doxxed.