You're right about that, it's honestly unfair for me to refer to Reddit as though it's a monolith. r/AskHistory is as good as it's ever been, r/WhatsThisBug is always fun, and lots of little niche subs are just vibrant communities.
Unfortunately when it comes to the major news subs, the big issue isn't polarizing politics, it's just people using the headline to spout memes.