France's past system is irrelevant, since it was built at a time when renewables were completely noncompetitive. The world has changed now, and changed radically. Going forward, France will be going renewable too.

Sure, it's expensive, but all the things we'll have to do to have an all-renewable grid are pretty expensive themselves and unproven.

Yes, we should end up with a much smaller mix of nuclear than France had, to help optimize cost. But it is an option available now that we know will work, and I believe that the optimum point is not 0% nuclear. (In western democracies, though, nuclear has become practically impossible. This hasn't stopped a large amount of reactor construction in China, so obviously planners there disagree with your assessment).

Further, nuclear and wind are comparable in CO2 emissions, and PV is a few times worse. So if we really care about minimizing CO2 there will be some nuclear in the mix.

Betting everything on power->gas->power when we have basically no evidence that this will be economical at scale is crazy. Betting on pumped hydro or battery storage is also dubious. We should be pursuing all avenues available to us.

Also, making a pure opportunity cost argument is a little weird as well. The investments are not purely fungible. That's why we should both give extensive resources to ramp PV and resources to ramp nuclear and resources to ramp p->g->p, because they're not the same resources.

It is not an option we know will work. The inability of France to replicate their previous putative success means we can't take any of that for granted.

We have evidence that nuclear will NOT be economical at scale. The evidence is there in a cavalcade of disastrous experiences, even in places like France were experience supposedly, by your reasoning, would have told us to expect otherwise.