I think there's a more fundamental issue at play. Two people, both rather intelligent and completely sane, can come to complete different conclusions on things. For instance, I think fertility is one of the most critical issues facing civilization in modern times. I can offer reasons why, though you've already done so yourself in part, but that's outside the scope of this post for now.

By contrast, others may see the fertility crisis as not even an issue, let alone a crisis. After all humanity's not going to go extinct anytime in the foreseeable future, and billions of people is a lot of people. There are even some who think it may be a good thing - fewer people could reduce the impact of human emissions for instance.

So this difference in worldview would lead to radically different perspectives on seemingly completely unrelated things, like LGB representation in childhood education. Add in a bit of a radicalism and these otherwise reasonable disagreements gradually breed extreme hostility.

And I don't think there's any real solution here. No side can ever win, because neither view is really wrong. The best solution is probably general decentralization. But most people don't realize their opinions are opinions, and think they are factually and objectively correct - and want to impose their views on everybody, which trends towards attempts at centralization, inevitable collapse, and repeat.