From this book review:
Three hundred years ago, we burned wood for energy. Then there was coal and the steam engine, which gave us the Industrial Revolution. Then there was oil and gas, giving us cars and airplanes. Then there should have been nuclear fission and nanotech, letting you fit a lifetime's worth of energy in your pocket. Instead, we still drive much the same cars and airplanes, and climate change threatens to boil the Earth.
"Where is my Flying Car?", by J. Storrs Hall, is an attempt to answer that question. His answer is: the Great Stagnation was caused by energy usage flatlining, which was caused by our failure to switch to nuclear energy, which was caused by excessive regulation, which was caused by "green fundamentalism".
Counterfactuals are fun! I think I dismissed them too quickly as unknowable for a long time, but as with mot things, there can be better and worse arguments for how things could have turned out differently.
The environemntal movement is an interesting case, because what is considered good or bad in that context depends very much more on culture than on a problem solving strategy. The underlying conviction that human activity is inherently destructive leads to moralizing calls to give up things, that are not very effective. Whereas the obvious alternative is to improve technology to do more with less environmental impact. But that does not fit the narrative; to berate people and make them feel quilty lets one feel more morally superior and pure.
Would climate change never have become a problem, if the environmental movement would have empraced nuclear power instead of crippling it? No one knows for sure, but it certainly is interesting to think about.