That’s probably more of an artefact of France building exact copies of the same design within a relatively short timeframe (ten years) so they all shared the exact same design flaws and started showing their age at the same time
Thus ‘ramping up’ is a problem. If they want to replace 5% of their electric grid per decade with nuclear then it’s not an issue but that’s not going to solve short term issues. Go a lot faster and they trade short term problems for longer term issues.
