That's tautological and irrelevant. Yes, humans are most dangerous to every other life form on the planet. That's why humans rule the Earth, and not some other life form. But in terms we care about - humans being a danger to humans - we have some handle on it.

The worry with superintelligent AI is that it'll dethrone us, and automatically make it the most dangerous thing on the planet. In particular, more dangerous to us than we already are to each other.

I mean, so far yes. At the same time we have tons of people spending billions of dollars to make sure that's not the case, and I'm pretty sure they are going to succeed.