Of course it’s not the solution. Much like geothermal isn’t the solution, or wind isn’t the solution. They’re all tools we need to be using, right the hell now.
And the decades long startup time for reactors is solely a mater of political will. There’s no reason we can’t have modern nuclear power plants up and running in the span of a couple years, rather than decades. These aren’t the rinky-dink 1960’s reactors that melt down if the operator is an arrogant capitalist asshole. Modern designs take that choice out of human hands—if things go sideways, they self-terminate.