Is not their method of resolving conflicts to simply seek out further affirmations that their pre-conceived notions are correct, or did I miss something?

Yes - and avoidance - big time. (essentially, intellectual cowards - because the psychological pain is too hard to bear).

Is this nothing more than the classic "our news is honest, theirs is propaganda, our glorious leader, their despot" sort of rhetoric that leads so many to willingly inhabit echo chambers?

Did I just answer my own question?

No you didn't. lol

It's not a question of our side v their side. ( I'll change my position on anything if truth and facts lead me there)
Accepting dogma as truth - in the face of factual evidence is a state of delusion.
Delusion is a mental illness.

breaking through delusions can be long gentle process- or a traumatic, sudden one. (from how I understand it)