[magicalist]

I think the GP's point is just that there is unaccounted-for information about existing in the physical world encoded into that embodiment. AI will also have embodiment, and there will necessarily be information stored there, but a great deal of operational information will have to be learned and explicitly expressed in the AI itself. To use your example, an artificial organism could be made of coordinated colonies of machines, but cells already have a huge head start in the way they bind to one another, transport materials within and without, respond to various signaling agents, etc. Down to the basic molecular building blocks of the cellular machinery has been selected to (attempt to) optimize operation across all actions that cell might take.

The argument isn't that that embodiment is necessary for the artificial system to learn how to operate in a way that's as capable or better, just that there's a whole lot of information there not accounted for in the genetic code alone.