We process information at the rate we do because that's what works for adaptation to our environment. That's how all biological things develop. Some things are

We process information at the rate we do because that's what works for adaptation to our environment. That's how all biological things develop. Some things are remnants of old adaptations, but generally speaking, we are the way we are because that's what enables our survival. If it seems "slow", it's because it doesn't need to be faster. Better questions would be, why are we so weak? Why are we defenseless? Why are we hairless? Why do we move so slow? Most other mammals our size are much better equipped for survival. Obviously other beings "perform better" in many ways. Yet our fleshy, weak, slow, gangly, shivery bodies are suited for thinking, for adapting, for communicating and collaborating. However unoptimal or "slow" these authors think our brains are, they are obviously perfectly capable for what they need to do, seeing as we dominate the entire planet. In any system design, every decision tends to be a tradeoff. You can gain CPU power, but it will cost you energy, heat, and probably stability or longevity. You often do not know what a "feature" will do until you add it. So it's wiser to only add the features you need to accomplish your immediate goals. If at some point in the future, our survival is existentially threatened by our lack of "processing power", our brains will adapt. Until then, leave well enough alone.