Imagine this (not so) hypothetical scenario:

Yellowstone or another supervolcano erupts and leads to a few years of volcanic winter, where there is much less sunshine. This has historical precedent, it has happened before, and while in and of itself it will impact a lot of people regardless of anything else, wouldn't you agree it would be better to have at least some nuclear power capacity instead of relying solely on renewables?

Sure, such a scenario is not probable, but it pays to stay safe in the case of one such event. I would say having most of our power from renewables would be best, having it supported by 10-20% or so nuclear with the possibility of increase in times of need would make our electric grids super resilient to stuff