We would be doomed? Somebody should have told France who had a clean green grid 40 years ago.
If everybody had simply done nuclear we would be 10000x better of now.
The false promise of solar/wind held up by fossil-fuel and anti-nuclear people prevented green energy grids for literally decades.
If anything we are doomed because it took so long to actually bring solar/wind practically into being.
If we invested in nuclear and its advanced reactors decades ago, like we did in the 60s/70s we would also have high temperature reactors that could do things like provide industrial heat for chemical processes such as water desalinization, synthetic fuel production and so on.
You could even do very high temperature reactors if you wanted to decarbonize even chemical process that take 1000C without going threw inefficient electricity production and heat generation.
But coal plants were cheaper to build and that's why id didn't happen. Imagine a world where the US had build 100s of nuclear plants. The amount of nuclear engineers that would exists, the amount of knowledge and innovation that such an industry could have.
The problem is in the 70s what mattered was price, that coal plants were horrible to human and the environments was not considered.
So please explain why depending on fission would doom anybody. Germany could have replicated what France did in the 70s and simply started to build nuclear reactors when they started their green revolution 20 decades ago. In fact had Germany done so they would like be closer to fully de-carbonized now.
Literally any country that wants to be 100% green can right now call South Korea and order X reactors and within 10 years all but the largest industrial nations in the world could be 100% green power.