That's what baseload is.
> Renewables sometimes produce pretty close to 0 energy.
Which is why they need storage, and storage is expensive. If you do half nuclear and half renewables, you only need half as much storage.
Less than half, because you can use pricing to shift demand.
Suppose you have 50 GW of nominal demand, but solar generation is at 10% of normal because it's overcast. You can get demand down to 40GW through price incentives. If you had 50 GW of solar which is down to 5 GW, you would need to cover 35 GW from storage. If you had 25 GW of solar which is down to 2.5 GW, and 25 GW of nuclear, you only have to cover 12.5 GW from storage. Less than half as much.
Baseload, is really minimal load in the grid. There are many ways to produce the minimal amount. Real difficult part is to provide the max load demand on the grid.
Basically current nuclear technology is inflexible in economic terms (also quite a bit in practical terms), shown historically by most grid storage being deployed when nuclear was being built out.
If you instead use renewables, batteries, and power-to-gas you can also reach net-zero emissions without waiting twenty years until you have enough nuclear plants. Renewables and batteries are already cheap enough to compete with fossil fuels, and provide enough stability to reach a high percentage of the energy demand. 50% renewables is doable with hardly any storage at all. Power-to-gas can provide the storage needed for seasonal variations, but there are still cost problems with that.
Imo the lack of political will for the energy transformation mostly takes the form of unpriced externalities for fossil fuels. There still is no carbon price that is even close to the actual damages. Damages from the extraction of fossil fuels are not paid for by the companies either. Coal plants still emit tons of Mercury without paying for it. Aviation fuel is essentially untaxed. The list goes on and on.