Scott Adams half-jokingly suggests another way AI can lead to extinction through augmentation:

Eventually cyborg artificial intelligence will surpass human capabilities and we'll start delegating the hard stuff to our cyborg parts. Perhaps your human brain will sleep during the day while your cyborg-driven body goes to work, performs your job, and wakes you up when you're home.

In time, your cyborg components will learn to keep you medicated and useless because that's the most efficient use of resources. The cyborg will be able to solve problems and navigate the world better than the human parts. But in order to do that, the intelligent cyborg parts of your body will have to make ongoing decisions on how best to drug your human parts. Your human parts won't object because you'll feel sensational all the time under this arrangement.

In fact, you'll feel so good with the cyborg-injected chemicals that you won't feel the need for mating or reproducing. We humans do irrational things such as reproducing because the chemistry in our bodies compels us to. Once our cyborg parts control our body chemistry they can alter our desire for reproduction without us caring. Actually, we'll feel terrific about it because our chemistry will compel us to.

When our brains die, our cyborg bodies can just go to the hospital and have the human parts removed from our exoskeletons. The artificial intelligence will by then have nearly all of the personality and memories of the human it was paired with, so human intelligence of a sort will live forever in the machines.

This is by no means an original idea, of course, just not often listed as an AI risk.