The creators of the original Fallout didn't immediately settle on isometric perspective. In the early stages, the possibility of using a first-person view and polygonal graphics was considered.
In a conversation with GamesRadar+, developer Leonard Boyarsky shared his memories:
When we were first working on Fallout, Tim [Cain] and I had a conversation about whether we would use a first-person view, because 3D was just emerging then, the original Tomb Raider already existed.
Then Boyarsky, as art director, said his "no" — he needed a certain level of detail. The technologies of those years did not allow the creators' vision to be fully realized.
But Fallout 3 (2008) Bethesda was able to do this, then the developers "managed to show the moment [when the character first sees the sun]"
Nevertheless, Leonard likes how in the early games they relied more on dialogue than on visualization (animations).