Specifically with the Fallout series, I think that one complication is that there was a lot of unhappiness way back when with the series moving from a much-liked isometric, turn-based/real-time game to a 3D game with shooter elements. A lot of people, including myself, didn't think that it would likely reproduce what they liked about the series. And, well, it was a change, but what ultimately came out was pretty good, and while I'm sure that it didn't cut it for some people -- you had things like the Wasteland series continuing the isometric approach -- I think that it was a pretty decent transition. The same people who liked the isometric games generally liked Fallout 3 and Fallout: New Vegas. So in that case, the game series was taken through a major shift that a number of players were skeptical about, and it generally worked.

But with Fallout 76, I think that the transition caused tradeoffs that didn't work out as well for many players.