I haven't been paying close attention but it seems to be doing well. I originally joined the Fediverse on kbin.social because I liked the idea of supporting an alternative to a Lemmy monoculture, especially given what I'd seen of Lemmy's devs' views, but over time it became apparent that the lone developer of kbin wasn't intending to take advantage of outside assistance and that it wasn't going to work out as a single-person project in the long run. So I'm glad mBin forked, it seems to have picked up the necessary momentum. The mBin instance I'm on has had the occasional downtime or bug but nowhere near the kind of trouble kBin routinely had.