You can’t standardize manufacturing of multi billion dollar facilities. Economies of scale just don’t work that way. Even residential housing has the same problem. There’s too much variation in on-site construction.
https://worksinprogress.co/issue/liberte-egalite-radioactivi...
There are minor variances locally, but you can make enough components common to benefit massively from economies of scale.
There is a lot of variation of layout possible within the constraints of the standard. However the vast majority of the hard work is done in a factory to standard sizes, and the onsite work is just final assembly to easy to change specs, so there would be no advantage to a standard.
The whole point of stud frame construction is that you can do basically whatever you want because it is overbuilt and all the connections and joints simple.