Baseload is a cost optimization strategy only relevant if your non-dispatchable power generation is cheaper than your dispatchable power generation.

https://en.acatech.de/publication/baseload-power-plants/

Solar produces incredibly cheap power for the daytime hours, pushing any nuclear off the grid (why would a data center buy expensive nuke power in the hours when cheap renewables are available?). Nuclear needs to be running and selling power at its high price 24/7 for it to be even close to economically viable. Only supplying power that people want(due to its high price) during the night is fatal to nuclear.

base load demand does not mean it has to be met with a constant matched source, and in fact that no longer works economically.