To build on this point, even the discussions which aren’t literally US politics are predominantly incredibly negative. To a degree that’s the internet these days, but Reddit exhibits it quite strongly.
That is also a HN thing, sadly. At least on reddit, it is easier to find a different community.
but reddit is topical. If you frequent only well-moderated communities you don't really have that, even in political subreddits. E.g. r/machinelearning, r/futurology, r/goldandblack