I'm willing to go out on a limb and suggest that the workings of the human brain are still far more complex than that of our digestive system. If the amount of effort that has been put into trying to emulate the former with software had been put instead into trying to emulate the latter, I reckon we'd pretty much have it cracked by now (as in, you could feed some tool info corresponding to all the inputs into our digestive system and it would be able to spit out exactly what outputs would be produced in the average human). But unlike AI/ML, not enough people, ahem, give a shit...
Not sure I agree, but accept it's not my area of expertise.
We don't necessarily want to simulate the human brain the way it does actually function biologically, rather simulate the its most useful behaviors, which are hard to see as being intrinsically linked to the workings of the gut.
There's an imperfect truth to the comment you're replying to.
You're right that it's unnecessary to emulate the brain down to its finest implementation details, down to the molecule or even down to the cell.
However, I contend that it's essentially impossible to create a "relatable AI" (an AI that behaves and thinks like humans do) without proper consideration of embodiment. A large part of why the brain works the way it does, at a macro level, emerges from the vehicle it's in, and broadly speaking both its afferents/inputs and efferents/outputs.
