They have the possibility to be good echo chambers. Or bad ones. But that they are echo chambers shouldn't be in dispute.

Academia constantly struggles with being too siloed. People recognize that the chambers tend to be too strong; they organize interdisciplinary conferences and programs and such to try to get around it, recognizing that a lot of the most important and transformative work is done at boundaries (e.g. psychology + economics).

But the echo chambers persist, and generally the sentiment is that it's a bit too strong: echo, good; degree of echo: not ideal.