Yeah, nuclear is temporary, and yes, nothing stays in place longer than a temporary solution, but it’s a known and can be built now rather than yet another 5-15 years of waiting for untried tech solutions.
I guess you could say nuclear power can be built "now". From a certain point of view.
The last nuclear reactor to go online in the United States took 14 years to build - from breaking ground in 2009 to going online in 2023 - at a cost of thirty billion dollars.
And that wasn't even a new nuclear power site, it was a additional reactor added on as an existing site, so planning and permitting and so on were significantly faster then a new nuclear power plant would be.
So yes, we could start the process of building a new nuclear reactor in the United States and commit 30 billion in taxpayer money to it. And after 20 to 30 years that reactor might come online.
Or we could commit 30 billion dollars to subsidizing wind and solar power, and get that power generation online in the next few years, at a significantly lower cost per kilowatt.