Reddit sheds a few million of its active users but the API changes and death of third-party apps don’t completely kill the site because now it’s pretty mainstream and a lot of people actually don’t give a shit about Apollo, RIF, etc.

A few million is plenty to make lemmy a comparable community. As that continues more and more people who didn't move in previous years will move now, because there are enough people here to make it worthwhile.

I think the main difficulty of a site replacing Reddit is that Reddit clones are now a-dime-a-dozen.

Which makes a federated system like lemmy even more competitive.

I've given lemmy a try 3-4 times over the last couple years. And I think that presently it is getting fairly close to a big enough crowd that is very usable and is comparable to what reddit was like in 2008 when I switched from Digg.

To be honest. Lemmy doesn't need to out compete reddit or whoever. It just needs to be competitive. Not having the brain dead mainstream masses over here is not a loss. However, people have always moved to the platform with more liberty when most other aspects are the same. Otherwise reddit would never have been a thing. Most people were over at Digg for a reason. They only moved to reddit when Digg gave them enough reasons to leave.