I cant confirm first hand, but do have second hand reports from friends that FO76 is in a very good state now. A quick look at steam has a 'mostly positive' review score now too.As I recall, some of the reviews for F76 were not good which is why I never bothered with it. Then, I think Bethesda added subscription fees, which made it even less interesting. Maybe that's changed, but then Microsoft bought out Bethesda.
I think it was prey to the usual AAA modern game release model of 'release in alpha status, take money, deal with issues later'.