It's more popular than Usenet! Take that, nntp.

I sure hope not

Yes

I can't foresee Lemmy specifically reaching levels of popularity comparable to platforms like Twitter or Reddit. Barring some very strange disastrous upheaval of the whole landscape they and their ilk will continue to be Leviathans even with decisions at the top that look like outright sabotage. There is so much inertia. Maybe those two examples might disappear, but only if they're devoured by another just like them.

I can see Lemmy and similar Federated platforms with their quite sizeable yet comparatively miniscule user bases carrying on as they are and even growing a little bit and having some effect on the zeitgeist with the occasional piece of local culture seeping in to the wider platforms though people there will likely not know that's where it came from. I also think efforts like Threads or likely something similar that comes after will be where the fediverse meets any mainstream success essentially becoming part of those bigger platforms in some way I can't yet predict in detail.

The big appeal of Lemmy is ideological and technical, this will always limit the number of people drawn to it. If there weren't already giants in this space that wouldn't matter because there'd be a snowball effect that would draw crowds who came because of other people not because of any interest in how the platform functions or ideals to pursue and with those crowds could come more crowds until you have a critical mass. But with the situation as it is now, the big crowds that draw yet more crowds still, are elsewhere so you'll only ever have enthusiasts or ideologues that go out of their way to be here.

Not unless it gets a good marketing team.

I wish

Which instance?

I don't think the form of Lemmy as a federated service will be able to scale.

What I expect is that, if Lemmy is successful, it will be as a platform for various Reddit alternatives, kind of like how Truth Social is Mastodon.