Honestly, I think the only true antidote to this sort of thing is to foster spaces in which people of vastly different opinions and positions can come together and communicate in a civil and genuine fashion. Pushing back on biases and presumptions through antagonistic or challenging conversations seems the only tried and true method we have for getting to the "truth" (or, more realistically, how little we know of or can grasp the actual truth whatever it may be).
It's hard, especially online and many just don't have the behavioural and cognitive muscles for it at all and very few in the world are actually strong at it.
Moreover, the moderation task would be monumental, which is why I'd think there'd have to be community buy-in from users/members and a grass roots enforcement of the ideals of the space as well as probably a good amount of gate-keeping unfortunately.
Additionally, I suspect that the technology of the platform actually has a role to play in fostering such a space. The technology is never a complete solution, but I think in such heated environments what's missing from real life are contextual and gestural cues and meta data that we can all use to moderate how reception and reaction to any statement. Social media basically allows for none of that. But there's no reason that we can't try to represent a post/comment/statement in some way that tries to capture the sentimental and gestural context it is being made from. I think this is an example of modern technology actually losing sight of the mission of humanising technology.
EDIT: It would be an interesting idea for a lemmy instance, to try to foster such a space. Maybe it has no users of its own, just communities? When it comes to gate keeping, it'd be cool of lemmy allowed invite only community subscriptions or something similar.