I'd assume people move when something better comes around.
But "better, more functional" is a relative term. Not sure that many here would be willing to forgo federation, and thus the independence from corporations, which especially don't like piracy.
Btw, have you specifically told people what about the UI/UX you find problematic, so that it could be improved?
And has kbin the same issue for you (as it federates as well, you can travel this community through kbin just fine)