Only the up front costs are insane, reactors pay for themselves in 30 years then keep going for another 30, then get extended for another 20.

Baseline power does support renewables, if it’s not nuclear it’s more fossil fuels. You need to generate four times as much energy if you are going to store it, for example as potential energy, then turn it back in to electricity again.

The intermittent nature of wind and solar is a real problem but not one that would stop them from giving a good average power output for the year. It instead means we still need a large capacity of energy generation with load following, which Europe had with oil and coal. A good baseline also helps which Europe has in some places with nuclear.