This isn't a game of Top Trumps where you need to find any one stat that's higher than your opponents to declare victory.
Nuclear has to be better than wind and solar and hydro and batteries and everything else (demand response, better insulation, undersea grid connectors etc.) all working together across a wide range of metrics to find a place in a modern grid.
It is failing at this. The alternatives are cheaper, better, greener, safer, quicker to build.
Narrowly focusing on one tiny aspect does not change this big picture reality.
The problem with what you're saying is that to supply peak power at all times could require building capacity in each method to supply full power, in case the others all fall to zero power. And even then, you hope that they don't all fall to zero, I guess.