[chronofar]

I find 2 (dangerous) scenarios to be most likely, one easier to reason about than the other:

1. Access is not uniformly distributed, thus some entity uses it to create immense inequality.

2. The AI becomes sufficiently intelligent and powerful that it looks at humans the same way we look at monkeys and treats us similarly (in other words, not overly concerned with human flourishing or even survival while commanding resources humans need to survive and flourish).

Neither of these necessarily mean "destroy" humans, and neither are by any means guaranteed (though #1 seems almost a foregone conclusion) but it could very well lead to an existential threat.

It's also possible we get a combination of the 2, wherein a subsect of humans can merge with AI but it is inaccessible to all.

There are other less existential concerns as well though, such as at what point does such a system become conscious and deserve rights? I'm not confident we really have any idea how to ascertain that, and bumbling into it could be tantamount to torture.