Oh, yeah, Fallout 76 was the saddest thing I've ever seen. The basic idea was shit (a fallout game without NPC's? Really stupid to start with), and the implementation was somehow worse. Fallout as a franchise might be dead because of it.
That's fair. Consider modding the game with the unofficial patch to get it to work better. But I do think that despite the errors, NV is just so much better than the others, because the story is that much better.
No, I've played 4 and New Vegas, and even despite my bias towards 4 because I've been to everywhere there in real life, New Vegas is clearly better. The story of New Vegas is simply excellent, and the DLCs are definitely worth it as well.