There is an astronomical difference between vestigial organs/nerves/what have you, and a required biological function which renders the individual totally incapacitates and utterly vulnerable for 6-10 hours. Especially considering the "natural" state of things where even giving the benefit of the doubt you will avoid predators which can kill humans, you may be sleeping under a rock or a tree and susceptible to bugs, rodents, germs, etc. I don't feel that your rebuttal really, well, rebutted his point.

It seems like a big difference but it occurred very early on in the evolution of life, so it's a disadvantage shared by all animals.

How about another example: mammalian females giving birth through their pelvises. This caused the deaths of countless women and children throughout human history. It's not as much of a problem for other mammals but it's a huge problem for humans. We've had to advance modern medicine to the point where we can safely perform major surgery (caesarian section) in order to mitigate it.

The book Sapiens has a few pages on this. Essentially, the thought seems to be that we're an edge case that's been able to jointly optimize for intellect/large brains and small efficient bodies by overcoming the limits on brain size imposed by vaginal birth. This in part explains our relative immaturity at birth. We're vulnerable and require constant care for the first few years of life. Compare this with other mammals such as calves which are able to walk roughly at birth.

> It seems like a big difference but it occurred very early on in the evolution of life, so it's a disadvantage shared by all animals.

It's possible that you could have sleepless neurons. But they would be so different than neurons we are stuck with that we might need to wait few billion years for them to show up.

Well the environemnt greatly changes in a 24 hour period which would have had a large affect on the evolution of agents. Typically for a period of each day its dark and cold, not a very efficient time for an agent to operate on average. Perhaps its more effective to be productive during the time when they can see easily, and its warm so cold blooded agents can operate and then an ecosystme builds around these things etc and its no longer about jst the physical ebvironment but the ecological niche an agent is operating in. So no point being active at night if the flowers aren't awake, and the bugs that feed off the nectar aren't there, and thus your food isn't about.