Eh most FOSS stuff i've used has actually worked out decently despite the mediocre user experience, not saying i've not had any dogass experiences with some things though. Imo lemmy isnt too bad but deffo could be better.

It's worth a try at the very least, and the reddit subs blackout will probably bring a few more people in. But to be realistic it'll probably be quite hard to start from scratch and to make it back to even a fraction of how big the old aub was.