Fallout 76 is a lot better than what it was at launch but it’s still nowhere near close to Starfield. It’s a weird mesh of ideas that don’t really fit together but are still enjoyable separately.
Try setting a budget and looking for the GPU that fits within it, everything else more or less builds itself from there as you check the recommended CPU pairings and requirements they have on your other components.
The problem with PC is always going to be the amount of possible hardware variations, it’s difficult to make sure the game is well optimized for all of them.
It also doesn’t help that some people don’t understand that they need a good CPU as well as a good GPU and end up with a massive bottleneck.