You are playing fast and loose with facts mixed in with a lot of wishful thinking so this is a difficult conversation.

Cheap is really relative: I've found very little information on the original build out of french nuclear and how much it cost so let's assume it was cheap. Do you factor in the cost of decommissioning and nuclear waste storage? This will cost literally hundreds of billions. And actually for how long? I did find an interview with the recently deceased chairman of the EDF from that time, who claims the plants were designed to last just over 30 years [1]. To paraphrase: the steel used will develop cracks but this is not a real problem because if will happen after the plants' lifetime of just over 30 years. France tried to build replacements 20 years ago with the EPR, but they were unable to finish the prototype in Flamanville, so they are stuck pretending the current plants can be extended infinitely. They are just kicking the bucket down the road, eventually it will come to an end.

Switzerland does not have some of the oldest reactors it has the oldest reactor, Beznau, which went online 54 years ago, the others are from late 70s and early 80s. Speaking of cracks, it was reported in 2015 there were a thousand holes near the reactor [2]. The operator denied it, but the plant was shut down for a while and the operator said there were 2.5 billion Francs (roughly dollars) used to increase safety [3]. This should give everyone pause to audacious claims that nuclear plants can run for 80 years no problem, and once you've built them they are cheap to run. In the US, it was lobbied hard to prevent Diablo Canyon from shutting down, and when it was approved, they said: but now we need a billion dollars to be able to even run [4].

Germany's energy transition started just over 20 years ago, not 30 years ago. During this time, the renewable industry was basically invented, the feed-in tariff system was invented, and it's been a huge success worldwide. This year alone around 400GW of solar will be deployed [5], non of that would've happened without Germany's decision. Since the last nuclear plants in Germany were shut down, coal use has been at a historic low. Poland's plan that you are in favor will have Poland end up with 30% coal in 2040, if all goes well. So a bit better than where Germany is basically at now, which is pretty bad for something that will happen 20 years from now at best. Poland's wind energy increased to 10% of the electricity mix in the last decade, so the german energy transition has done more to curb Poland's coal use than anything else thus far. And a lot faster than 20 years.

There is no special energy crisis in Germany that did not affect the whole Europe last year. France has pumped in 100 billion euros in the energy sector in the last three years to protect consumers and curb inflation [6], and was one of the first countries to do that. Germany only did it this year and much less (e.g. price caps at 40kw/h but only for 80% of your previous usage to promote saving). The countries are bickering now because Germany has a free market and no state company to pump money into, and it has a problem competing with "electricity" that is heavily subsidized [7].

Those are the facts.

The rest on how nuclear plants should be built, how long it will take etc. it's mostly just wishful thinking. You don't know any of that, so there's nothing to comment on.

[1] (in french) https://www.ina.fr/ina-eclaire-actu/president-edf-risque-fis...

[2] https://lenews.ch/2015/10/13/concerns-raised-about-switzerla...

[3] https://www.axpo.com/ba/en/about-us/magazine.detail.html/mag...

[4] https://www.reuters.com/business/energy/us-approves-conditio...

[5] https://about.bnef.com/blog/3q-2023-global-pv-market-outlook...

[6] (in french) https://www.latribune.fr/economie/france/crise-energetique-l...

[7] https://www.bloomberg.com/news/articles/2023-09-18/france-an...