You don’t need to install X-amount of global demand. Battery/hydrogen storage can solve the issue as has been demonstrated repeatedly in various research. And with home battery solutions you can even fully decentralise it.
I don’t understand your centralisation argument, nuclear is about the most centralised power source there is. And it can be threatened, as seen in the current Ukraine-Russia war.
Solar and wind can scale up to the demand. Nuclear actually has a much harder time doing that, as materials are far more rare and expensive, and it takes much longer to build. If anything, the time argument works against nuclear, not in favour of it.