I came late to Reddit myself but even I noticed that happening during the pandemic. The decline was rather speedy, sharp, and extensive (affecting all subs).

And we could even track some of those to specific implementations or lack thereof of features by Reddit. Like how their search feature sucked so bad, thereby encouraging people to write a (still yet another) post to ask rather than look up an existing highly crafted and well-researched answer that even if posted a mere week prior still would not show up in the algorithmic feed pushing all the latest noise to the absolute tippy-top. And mods were forbidden from pinning more than two posts. And even those only showed up when sorting by Hot. And maybe not even then in some apps. And you couldn't consolidate ones bc the moderation tools sucked so damn hard, e.g. posts made by Auto Mod could not be edited later by the very same mod team who requested that the post be made. Every damnable one of these things increases apparent engagement metrics like "number of posts", but at the expense of actually connecting people with the information that they wanted to receive. :-(

To which we can say "fuck spez", but it's deeper than that bc of the chasing after profits to the expense of all else that led to that, as in if it wasn't him that did it then it would have merely been someone else instead.