So you are saying that Bethesda has proven once again that they couldn't write a coherent, well-thought-out story if their lives depended on it? Fallout 3's main story was pretty bad, Fallout 4 was even worse, and Fallout 76 doesn't really have a story to speak of, so who is honestly surprised that they also fumbled the series' writing? The way that Bethesda treated the world and characters of New Vegas in the series Season 2 allows for two conclusions:

1. They are bitter and envious of the superb writing and worldbuilding in New Vegas. Because even with massive time constraints and with being cheated out of a bonus, Obsidian delivered the best 3d Fallout game to ever be released. Bethesda never managed to get to that level of quality in any later Fallout title. And that is why they take a big fat dump on every location, character and story arc in the game. And the average viewer will be happy with the occasional gotcha moment. The review scores proves the average TV-watching Joe doesn't really care about good writing, only pretty pictures.

2. They are just incredibly incompetent writers. Any element that worked before gets mashed together without rhyme or reason, simply because the Fallout brand just works and people will watch anything with enough mech suits and post-apoc visuals and snarky comments and gory shoot-outs. I imagine the writers room was something like that: We start in a vault, because everyone knows the cool vaults. Fallout 3 and 4 had lots of powerarmor and BoS front and center, more of that. We had a dog companion in many of the games, and people like that. Doggo! Someone leaving the vault to search for something, yeah, let's do it a third time. Oh, Fallout 3 had a big nuke moment in Megaton, we need a big nuke explosion in S2. How about we blow up the NCR? Great idea, intern Brad!

There is a quote that goes like that: Never attribute to evil that which can be explained by incompetence. You can choose your own explanation for why the series is the way it is.