If that's your take why is exactly nobody doing it? Oh, yeah. Because nobody has a clue how to actually pay the massive (and mostly paid in advance) costs.

Yet a lot of countries are proudly planning to build nuclear soon™ instead of those silly renewables, when what they actually would need to do is building much more nuclear than they are planning right now while also building massive amounts of renewables.

You are not actually wrong. Building more nuclear right now is an option. Building-up storage and infrastructure instead is the other viable one. Building massive amounts of renewables is needed in both cases.

The moment you show me countries starting nuclear in proper amounts right now, while also building and planning the needed increase in renewables alongside I will cheer for them. (For reference: energy demand increasing by a factor of at least 2,5 with ~35% production capacity needed for a solid base load means your minimal goal for nuclear capacities right now should be ~100% of todays demand...)

But as basically no country seems to be able to manage that investment the only option is storage and infrastructure. Is it costing the same in the end? Maybe? Probably? We don't know actually as decade long predictions for evolving technologies are not that precise (just look at the cost development of solar in the last decade for example). We know however that this is a constant investment over the same time renewables are build up to provide 100% coverage (PS: the actual numbers would be 115% to 125% btw... based on (regional) diversification of renewables and calculating losses through long-term storage).

Again: I'm not against building nuclear (and renewables!) right now, if that's your plan. I am however very much about the bullshit that is going on right now, where it's more important to show how smart you are by building some nuclear capacity (with the math not adding up at all) while laughing about others building renewables and spouting bullshit how it's just a scam to burn fossil fues forever.

Contrary to the popular narrative between building up renewables and storage and building just some nuclear capacities and some token renewables -if at all- it's not the former countries that are running on ideology with no actual real world plan.

As already said above: I totally support France' plan for 14 new reactors build until 2050, with a lot of renewable build-up at the same time. Because that's a workable plan. But that they already have problems publically justifying the bare minimum requirement of 14 reactors and the renewable up-build is a symptom of a larger problem. And basically every other country planning new nuclear power right now isn't even close to this scale and just living in a fairy tale world... or just providing an token effort while hoping for other bigger countries to solve the issue for them in the end.