It's gonna die like Digg or Fark ... Which are still around, but shells of their former selves.
TBH most normal folks haven't even heard of Reddit, let alone Lemmy or Mastodon.
I disagree with you on how well known Reddit is, it's been mentioned in enough news stories over the years that most people have heard of it, even if they've never been there.
AI means Reddit will always look alive at a glance.
Like you still get some people complaining that lemmy isn’t active enough for them to leave Reddit, even though they’re just hanging out with bots all day.