I think back to this article quite a bit, lately. The basic idea is that social media sites seem, by the numbers, to be doing fine, and then they abruptly collapse. The trick is that when the people who create high engagement - people who make posts that make people super happy or angry or whatever, as long as they are feeling something and therefor getting engaged - when those people start to post less because they’re spending some of their energy on some other new site, the old one gets kinda hollowed out. It’s not obvious it’s dying until it’s dead.

I don’t know if reddit is done for, but I can say that lemmy and mastodon are feeling a lot more fleshed out, lately, compared to past waves of people coming from twitter. It feels like turning a corner, or crossing a critical mass threshold; it’s getting easier to stay engaged and not feel the need to check the old giant sites.