Two things feed into the echo-chamber pattern, and both are chilling effects. One can be easily augmented and the other cannot.
The first is the voluntary tendency people have about providing their IRL identities. For some this is largely optional, for others, less so, for example when a celebrity is participating as themselves. Real identities means there's some skin in the game for at least some people, requiring a heavier hand in moderation. This part can only be augmented so much, and requires individual users to self censor, disengage, and conceal their own identities when posting an unpopular sentiment. Humans being what they are, this reality will never go away.
The other is the karma system, and this can be changed. And karma really is an unnatural ranking value, since one can pick up on inconsistencies after enough lurking. Whether it should change (or be changed) is arguable. If it's as harsh as it seems, and the effects are that chilling, it may just be an expression of actual human behavior. In which case, it's an early warning alarm, and an analog for what goes down in face-to-face meetings, but remains unspoken. We may not like echo-chambers, but they take shape in the real world too, in which case every social circle carries a shelf life that can probably be quantified by the manner in which this feedback loop widens and deafens its participants by jamming all signal with a noise that drowns out everything else.
I'd hope that last part isn't true (being slightly depressing as it is), and that tweaking the numeric validation could tune the ambient personality of the community's behavior, such that it doesn't drift into irrelevance. It sounds easy enough, but maybe poor execution would warp and deny certain aspects of reality, to produce yet another fiction with unintended consequences.
Anyway, I'm just gonna keep doing whatever.