We're not talking about mathematical optimality here, both from the solution found and for the time taken. The point is whether this finds results more cheaply than a human can and right now it's better on some problems while others it's worse. Clearly if a human can do it, there is a way to solve it in a cheaper amount of time and it would be flawed reasoning to think that improving the amount of time would be asymptotically optimal already.

While I agree that not all problems show this kind of acceleration in performance, that's typically only true if you've already spent so much time trying to solve it that you've asymptoted to the optimal solution. Right now we're nowhere near the asymptote for AI improvements. Additionally, there's so many research dollars flowing into AI precisely because the potential upside here is nowhere near realized and there's lots of research lines still left to be explored. George Hinton ended the AI winter.

The person said typical not always the case. Just because there are obviously cases where it didn't happen does mean it it's still not typically the case.