Not the guy you are asking but I think I could give some insight. I don’t think it’s going to “fail” in every regard but it’s going to decline significantly and become an echo chamber for the extremeist types that are driving everyone away. After all the more reasonable and normal active types have left the extremists will likely turn on each other over very minute details that don’t exactly correlate to their specific world view and it will likely turn into an all out brawl.

That being said Reddit is very likely to pull more stupid anti-user bullshit and send a few more waves of users to Lemmy and spike the numbers some more at which point hopefully has all their mod tools figured out and communities get solved to actually allow for niches to be usable.

The success of Lemmy lies entirely on a perfect timing of Reddit fucking up again before the infighting becomes too bad and people returning to Reddit warn people away from going to lemmy