The idea that, thanks to social media, we are all sorted into “echo chambers” where we only hear views identical to our own, is a commonplace. I think the whole idea of echo chambers is misinformed.
There’s a range of viewpoints close enough to your own that discussion is useful, and a range so far distant that no such discussion is possible. There’s no reason to suppose that this range will encompass the party political spectrum in some particular country. In the case of Australia/US that spectrum includes climate deniers and creationists (with a high degree of overlap).
Taking the creationist case because it’s simplest, what is the point of discussing evolution with them? And from their POV, while they are willing to score debating points where they can, they really can’t have a serious discussion within anyone who isn’t (at the least) a theist.
Admittedly, it’s useful to know what the other side is saying, if only to refute it in discussions with people who hold intermediate views, and whom we may want to convince or learn from.
But here the attack on the modern world social media falls flat. In the kind of one-newspaper town that used to be common, the existence of alternative views could be ignored more or less completely. Now it’s almost impossible to avoid them, if only in the caricatured form presented by the media of your own side.