Perhaps because that standard design didn't work out?
Even Switzerland is shutting down nuclear plants and they managed to build the longest railroad tunnel of the world without budget overruns and half a year before due date.
That's not so clear cut. Mühleberg near Berne has said that 2019 they didn't make profit, however the operator company BKW never published gains with that plant.
We managed to build these before the industry became expensive.
Now Germany and the United States are rushing to close the operating plants.
I’m not sure why we can’t figure out how to build a standard design and replicate it