Being able to speak is probably more important than being as smart as a human. Cultural / memetic evolution is orders of magnitude faster than biological, but its ability to function is dependent on having a memory better than mortal minds. Speech gives some limited non-mortal memory, as does writing the printing press, or the internet. These inventions enable more efficient evolution. AI will ramp up evolution to even higher speeds, since external memory will be replaced with internal 1) lossless and 2) intelligent memory. As such I am unconvinced that this would mean slower takeoff speeds. (You just explained that the most important factor in doing well as humans is something humans are not overly good at, instead of the special magic that only humans posess.)
Being able to speak is probably more important than being as smart as a human. Cultural / memetic evolution is orders of magnitude faster than biological, but its ability to function is dependent on having a memory better than mortal minds. Speech gives some limited non-mortal memory, as does writing the printing press, or the internet. These inventions enable more efficient evolution. AI will ramp up evolution to even higher speeds, since external memory will be replaced with internal 1) lossless and 2) intelligent memory. As such I am unconvinced that this would mean slower takeoff speeds. (You just explained that the most important factor in doing well as humans is something humans are not overly good at, instead of the special magic that only humans posess.)