In hindsight computation wasn't the important thing though. A lot of things require a lot of computation that aren't intelligent or don't scale well, like Deep Blue. The important breakthrough in AI was learning ("machine learning").
Search/Reasoning/Inference time compute, however you phrase it is still essential. You need search to improve upon learning to work in novel situations.
Humans do very little "search", as we can see in games like Go. Which suggests it isn't essential for AI either.