Because Greenpeace actively protested to prevent maintenance to some of them, lol. Use your brain, stop zealously repeating catch phrases and actually think critically.

Let me give you some examples, you said:

• “the country relies on nuclear energy for 70% of its electricity”

And all of that power is provided by 59 moderately sized buildings. 34 of them were built in the 70's and have been refurbished and maintained to this day, because mad irrational regulation doesn't let them just tear the damn things down and build newer ones that are more efficient and use recyclable fuel. You won't find a single wind turbine or solar panel that lasts over 50 years, none.

• “French electricity group EDF said Thursday that shutdowns of four nuclear reactors would be extended for several weeks because of corrosion problems, potenti…”

Ok, that wasn't this Thursday, that was some Thursday in 2021. Guess what? it was a design flaw only present on the N4 model. They closed those four, because there are only four of them. And they figured out how to fix them and now they fix them regularly and today all those four reactors are operational. They learned a lot and are now applying the same good practices to all the nuclear reactors to avoid corrosion issues in any of the plants.

• “France has pledged to reduce its reliance on nuclear power by shutting down 12 nuclear reactors by 2035”

Again, that was in 2014. A policy that originally aimed to reduce nuclear power reactors to 50% of the country's energy generation by 2025 amid the push of fossil fuel funded anti-nuclear activism. This was delayed in 2019 to 2035. But this year it was completely reversed. They plan to build 6 more instead and potentially expand that to 8 later this year. Because it turns out, they're really not that much more expensive than other sustainable sources and just as good at reducing fossil dependency now that Russia, the main oil exporter for EU, decided to blow their neighbor to smithereens.