I think it's extraordinarily unlikely that some technique can reach AGI but not reach ASI. It won't have the same limits to modification as human brains. Why would it stop at a level that's just slightly disruptive? If you can make an AGI you can make a better AGI, with no obvious limit. And that AGI can help further improvements, leading to the singularity intelligence explosion scenario. Assuming AI researchers continue with the same attitude toward safety as usual, and I see no evidence of this changing, the most likely result is the extinction of all biological life.