Neo-Luddites

Arguably if you give AI access to the nuclear launch system then it can cause human extinction "by itself". Every "by itself" extinction scenario requires some pre-existing circumstances so this has a right to qualify as one of those scenarios.

Contrary to before we now have general purpose AIs that can understand all types of scenarios and make decisions in them. This means they can cause extinction with less human guidance. And there's no strong reason to doubt AI could become as intelligent and autonomous as humans, probably in a decade or two. Then it's pretty much bye bye humans.