This is the idea of "hard takeoff" -- because the way we can scale computation, there will only ever be a very short time when the AI will be roughly human-level. Even if there are no fundamental breakthroughs, the very least silicon can be ran much faster than meat, and instead of compensating narrower width execution speed like current AI systems do (no AI datacenter is even close to the width of a human brain), you can just spend the money to make your AI system 2x wider and run it at 2x the speed. What would a good engineer (or, a good team of engineers) be able to accomplish if they could have 10 times the workdays in a week that everyone else has?
This is often conflated with the idea that AGI is very imminent. I don't think we are particularly close to that yet. But I do think that if we ever get there, things will get very weird very quickly.
If general intelligence arrived and did whatever general intelligence would do, would we even see it? Or would there just be things that happened that we just can't comprehend?