Thank you for the explanation!

It's difficult with academic researchers using terms with significantly different meaning from the public at large. I wonder whether it's more harm- than useful, as it'll typically lead to the public either misunderstanding what they say or dismiss them completely because they're "obviously talking nonsense".

The scientific research into echo chambers seems almost straw-man-y, e.g. "echo chambers are perfectly sealed to the outside, no contact whatsoever is possible", so they check and find "that's not really happening" because people might talk about politics with one group exclusively, but will also talk about sports so they're not in an echo chamber. Does that provide value, when they are in a political echo chamber?