Smaller communities strike me as more "natural" to engage with, by which I mean, the human brain (or mine at least) seems better equipped to engage with small groups of familiar people than a sea of usernames I don't know and have no real rapport with.

but when people say they create their own echo chambers Yada Yada thing, even though I would agree with that, it's interesting to see how people who believe different things, are just amongst eachother.

I think being exposed to the cacophony of "sound" online had given a lot of people strange ideas about "echo chambers." To me it's extremely natural and obvious that most people would gravitate towards people they actually like and broadly agree with, rather than toss themselves into online spaces where they're constantly at odds with the other users. Depending on one's perspectives and political persuasions, finding those spaces can be fairly easy, or very hard.