angel in space who falls in love with an astronaut floating out in the void, not realizing they've been dead for years out there nor comprehending what death even is. is that anything
It's easy to jump to the conclusion that the NCR and New Vegas got destroyed in the series purely out of spite, because Bethesda is coping and seething that people like FNV more than any of their Fallouts. I'm also leaning towards that interpretation myself, although I'm not ready to attribute that specific intention to Bethesda just yet.
A much more charitable, but also more likely interpretation is this: Bethesda has a very superficial understanding of Fallout, and they're incapable of going in any new and interesting direction with it. And that's why they destroyed the NCR and New Vegas, because they represented humanity rebuilding and looking towards the future (albeit still with heavy doses of old world nostalgia, but FNV has already said plenty on the topic). Their continued existence in canon forces Bethesda to think about the future of the setting, when all they want to do is sit in their postapocalyptic sandbox that hasn't been cleaned up in 200 years and wank about the BOS, Vault-Tec, and 1950s American aesthetics. So they had to go.
Well, whichever one it is, it's clear that Bethesda has absolutely zero respect for the work of Obsidian/Black Isle. Or the Fallout setting in general, for that matter.
The Tezuman Empire in the jungle valleys of central Klatch is known for its organic market gardens, its exquisite craftsmanship in obsidian, feathers and jade, and its mass human sacrifices in honour of Quezovercoatl, the Feathered Boa, god of mass human sacrifices.
As they said, you always knew where you stood with Quezovercoatl. It was generally with a lot of people on top of a great stepped pyramid with someone in an elegant feathered headdress chipping an exquisite obsidian knife for your very own personal use.