I think people care.

They care so much they actively avoid them.

What you’re describing is groups of people sharing opinions that can differ with one another in good faith discussion.

The problem is, this is what fashies consider an “echo chamber”. The definition itself is not applied in good faith by certain cohorts. For example, people having good-faith debates are “liberal” echo chambers, because not toeing the alt-right fascist line is never considered to be good faith.