I noticed the "eternal September" happening in years prior, as Reddit became more acceptable to the wider public and as a smartphone app rather than a forum host mostly for techies.

And with those "normies" came the low-effort posts that totally ignored things like stickied posts, subreddit rules, and the overall culture of the community (or site.) Take a look at /r/roms, for example. The sidebar, the top announcement sticky, the rules, and the automod on every single post says "here is where they are" and what is most of the subreddit? "How do I find game" - same thing for BuildaPC, or Tech Support, or Linux.

Then the mods have to remove the low effort posts and get called names, or they get upset that the resources they've taken time to make available to the community are ignored for the 500th time and blow up, just to get called more names or even censured by the admins.

The only way to win is to not play. And that's why I use a combination of HN and an RSS reader now.