France nuclear share stopped growing because of the terrible policies of François Hollande—the president with low-single-digit approval rating, who singlehandedly turned France's formerly largest political party into small fry, because people hated him so much.

And then Macron decided to continue the insanity by following up on Hollande's unfulfilled promise to close the perfectly functional Fessenheim plant.

Then there are the "market competition" policies. It used to be that the French grid was entirely run by EDF, a state enterprise. And it worked well enough. But then the EU (with buy-in from complicit French politicians) decided to introduce "privatization"—except it's totally fake, as EDF has to sell energy to the private companies at prices set (to much lower than the market price) by the government. This has hurt EDF financially, and combined with other lacks in investment during the past decade or two means that they have lost a lot of organizational competence (skilled engineers are gone).