Echo chamber is a weasel phrase by people who want to limit discourse.

Users will form groups, sub-groups, and cross topic groups with like minded people. The operative term “like minded” not clones.

There is disagreement with like minded Bitcoiners about self custody, lightning, spending vs hodl.

There is even stark disagreement in more woke circles but there are core beliefs (even if I disagree with them) that bind them to follow each other.

On the other side of things putting people with zero common ground together is a disaster too. Sounds good on paper and is bullshit in practice.