[bentcorner]

Makes me wonder how you could apply this to social media.

What if you had a social media site where you could only see the same set of people? (Say, 150 people - Dunbar's number)

This isn't perfect by any means, but how would you fix it from there? Would you make it mix the population every few months? Maybe just comments/reactions are restricted to your cohort but you can see all posts? Would you mix the population based on some kind of score? Could that score be multi-dimensional?

[TeMPOraL]

It probably wouldn't work, because social media is voluntary. People can just reduce participation, or just leave, and find alternative ways to get whatever value they were getting from the social media site. Users stay because it's fun, or because their friends are staying (network effect); your proposed interventions would both frustrate the users and weaken or destroy the "glue" that keeps them coming back.

In contrast, those natural social networks of yore - tribes, villages - were all-encompassing, and you were stuck with them. The modern social networks that are strong - school, university, work - also have this strong "like it or not, I'm stuck here with this people" component. Sure, it's easier to change a job than a tribe, but it's still costly.