Not the parent but every time this question gets asked here it usually gets a few responses along the lines of "the more specific the topic the better the content/community generally is" and I'd agree. A few I enjoy are r/homelab, r/programming, r/Economics, r/networking, r/AskHistorians, and r/ColorizedHistory.

It really depends on what subs you choose.

The defaults are cesspools. Just plan on nasty things being said back and forth to each other. In reality, the defaults are worse than 4chan, which is saying something.

However, the moment you start getting into tech subs and narrow hobby subs, the SN ratio cleans right up. Yeah, there might be a single spam, or some rude person, but they are the exception.

Reddit's like Usenet. The more people in a general group, the worse behaved they are. Go look up "Greater Internet Fuckwad Theory" -- so true..

I found some of the best stats/ml community out there on reddit. Try r/machinelearning and r/statistics.

Honestly I just use Reddit for entertainment. I know there are substantive subreddits out there, somewhere, but most of the subjects I care about understanding and discussing come through HN anyway.

You must use much different reddit then I have.

Which is actually a real thing, since each person's subreddits really do create a different experience.

/r/Neutralpolitics is great.

Yes. /r/politicaldiscussion isn't quite as good, and certainly has a certain 'lean' to it, but it tolerates differing opinions pretty well.