I don't necessarily agree, the Rust subreddit is fine (except for all the AI slop posts this year, which the moderators have a hard time keeping up with) and some of the more niche 3D printing subreddits are doing fine, basically it feels like the past few years haven't happened there. The Arch Linux subreddit is a bit chaotic, but the moderation is not really the problem I think.

Maybe all of these fall into your last paragraph and I simply don't frequent the type of subreddit you describe. The thing is, it is hard to tell if it is you or me who have a representative sample here, or if we are both off. Two samples is not statistically significant.