I'm not claiming that humans are somehow born with way more than a few billion parameters, no. I'm agreeing that we have an existence proof for the possibility of an efficient model encoding that only requires a few thousand calories to run inference. What we don't have is an existence proof that finding such an encoding can be done with similar efficiency because the one example we have took billions of years of the Earth being irradiated with terawatts of power.

Can we do better than evolution? Probably; evolution is a fairly brute force search approach and we are pretty clever monkeys. After all, we have made multiple orders of magnitude improvements in the state of the art of computations per watt in just a few decades. Can we do MUCH better than evolution at finding efficient intelligences? Maybe, maybe not.