Let's get the big one out the way first: No, Fallout 76 is not as good as 3, NV or 4.

It's not shit though, far from it. And the bugs seem to have been patched out because in about 10 hours I've not seen a single one.
The map is just enormous, there's so much to explore that I reckon it'll take over 100 hours easily.
As a single player game it plays fine, I'm playing it just like the previous games, a lone explorer shooting anything I come across.

The quests are a bit boring and this is the game's downfall, there's not enough to keep you playing unless like me, you love exploring.