And the real threats are mostly economic and environmental - the concentration of the means of production in the hands of few who use it to exploit us all, and a surge in energy usage accelerating climate change.

Even the sci-fi scenario assumes there is a discrepancy of capability between attacker or defender. If the 'attacking' system is (by some reasonable measure), 1000% as capable as a human, and the 'defending' systems are 60%, then it is a problem. If the 'attacking' system is 1000% as capable as a human, but there are hundreds of thousands of systems that are 900% as capable as a human, it's probably not going to take over everything successfully.

So unequal distribution of AI technology, and lax regulation and opacity of the biggest companies which actually make the risks the worst.

I don't think the "AI Safety" people are "unserious and out of touch" - I think they are actively making AI Safety problems worse by being advocates for consolidation of AI development and lack of transparency.