Feeds are optimised for engagement, and agreement is engaging. Follow and mute for a few months and you assemble a world in which your thesis is obviously correct and the other side is stupid.
For a trader the practical harm is a missing risk case. You cannot price what would make you wrong if you have never seen it argued well. Echo chambers are also where a pump finds its participants, because manufactured enthusiasm is indistinguishable from consensus inside the room.
Deliberately keep two or three credible sources who disagree with your usual positioning. The test of a good opposing source is that reading it is mildly annoying rather than absurd.
Related: groupthink, social-proof, confirmation-bias, finfluencer