[yedava]

Communities become echo chambers when a tiny minority of people who have too much time on their hands monopolize discussions. I'd even argue that this is the primary mechanism of echo chamber creation. Other mechanisms like the one OP mentioned aren't that significant a contributor in creating echo chambers.

[remir]

I think the percentage of the population that desire genuine and thought-provoking discussions may be smaller than those who simply want validation and being part of a like-minded group.