You're right, people weirdly lack imagination on what "higher intelligence" (minus ethics) actually affords you, let's have a look:
What do average people currently want? They're taught, the most important thing was being rich. So they will ask their AI to make them rich. Most real life ways to get there are "sketchy" to say the least, usually downright unethical and anti-social, but US society turns a blind eye when the "Wolf of Wall Street" comes out on top and the schemes don't easily fit into average people's abilities of moral judgement.
-> Large parts of US society suddenly engaging in all kinds of "semi-legal/hyper-illegal" fraud schemes, at the expense of already saturated environmental and societal resilience. Guaranteed collapse.
Or, let's get rid of those pesky neighbors/wrong-colored people/annoying opinions? Again, "legal" is a pretty squishy concept and only really applies when you don't have the legal expertise to get around it. Now you can.
Or, look at the basics: what is "real"? You only "know" because you trust certain people and institutions. Generative AI can help with that /s.
It's not only about "building weapons of mass destruction". It's about doing the same shit as usual, but a thousand times faster/amplified. Look up poly-/metacrisis for starters. Going faster with AI when there's a wall in front of you isn't the best idea.