I wouldn't necessarily be convinced of that. I'd put that in a similar category as climate change. It might catastrophically ravage the world, but I think humans would survive. It's not the same punctuated event as nuclear fission. If a crazy person got control of nukes early in, they could wreak havoc on the world. Initial blasts kill tons of people, radiation would likely not be fully understood and fallout changes the global landscape before humanity can realistically react. Contrast that with global warming and microplastics, we know (we as in humanity in the broader sense) these are issues. It might need to get to the catastrophic ravaging before enough people are convinced, but eventually it will happen. And the intervening time won't cause humans to go extinct. Sure billions might die, but not all.