I don't like the clickbait title at all -- Mastodon's clearly going to survive, at least for the forseeable future, and it wouldn't surprise me if it outlives Xitter.
Still, Mastodon is struggling; most of the people who checkd it out in the November 2022 surge (or the smaller June 2023 surge) didn't stick around, and numbers have been steadily declining for the last year. The author makes some good points, and some of the comments are excellent.
I made a Mastodon account during that blitz in '22. Yes, content wasn't there yet, but honestly, it was the interface for me. It's UI didn't feel simplistic enough to me as someone just getting started with it.
Lemmy may have faced a similar fate for me if it weren't for the smooth interface of Sync to be honest. I know many on here are leaps and bounds beyond my tech proficiency, but so many folks are still in the stone ages writing their passwords on post-it notes etc so to think that they'd adopt something like Mastodon over Twitter or Lemmy over Reddit seems like the bigger counterparts will always win just on sign-up flow and instant gratification.
Yeah, Mastodon's interface has a lot of complexities. It drives me crazy when people say "just like email" ... here's the most recent diagram of what posts are visible in your federated timeline.