When it comes to nukes in particular, I get the impression the belief of normal people is it can go all the way to Alderaan. Yes, even though that's wrong by many orders of magnitude.
VN swarms, while currently sci-fi and dismissed by normal people, are a much discussed outcome for ASI, and seem to be taken seriously in such circles.
Everything else, sure — us != planet.
I'm simply suggesting we stop talking in vague terms, and be honest. We want to preserve our lives not the abstract notion of all life on earth.
The absolute best thing anybody can do for the environment is to not have kids. That'd save vastly more emissions and resource consumption than buying green-tech-for-the-rich such as EVs and heat pumps.
I really doubt we'll be able to stop 8 billion people from having babies.
You personally may be better off being an engineer and getting paid to help develop mitigation technology.
And no, young people in general do not care that much about the environment compared to much more immediate issues such as poverty. Young affluent people in rich countries do, but then it might also be that we've spent the last decades literally telling them they'll die burning at 40 and they might not have understood that was hyperbole.