There are massive logical leaps here. For example, why does superhuman intelligence translate into AI taking over the world? By what means, exactly? You can respond to this with more sci-fi tropes - nanobots, mind manipulation - but come on.
I have plenty of misgivings about AI, but I think you can make a plot like that for anything if you get into the right mindset. Kamala Harris wins → war in Eurasia → nuclear apocalypse, Coke changes the recipe → soft drink extremists begin a worldwide terror campaign → totalitarian police state, etc.
>This could probably happen today: a pandemic could cause human extinction, and AI is capable enough to assist in biology research.
No, friend. Someone having access to abliterated fable 5 or whatever does not give them superpowers to create a human extinction level pandemic.
I've tried, gently, firmly, obliquely... nothing seems to work. I had the same experiences during the Crypto bubble, people simply wouldn't listen to dissent from the notion that we were on the cusp of changing money, programming, and society. How do you explain to someone that just because they can imagine an exponential graph doesn't mean the data fits?