That's not what the OP or the literal quote you pulled from them said. They said a single neuron is ridiculously simple _relative_ to what a clump of them can do.
Out of all that complex biology in the brain maybe just a small part of it is contributing to intelligent behavior. Most of it is for support or redundancy. So I don't care you can equal a neuron with a 3 layer MLP with 1000 neurons or more. A model that fits on a DVD can speak fluent language, write code, and solve tasks - that is the useful capacity we are looking for.
A hand looks simple to a child. to a doctor? orthopedic surgeon?
worse, to an untrained eye, your response looks like it is from an llm. it would explain missing the nuance. not the only explanation by far, but when combined with talk of genetic effects in the footnote…