An average might come out to 5 hours a day for food but I’d bet that’s not evenly distributed and looks a lot more like extremely long days spent hunting or gathering while plants are in season separated by times of very little action while you are basically starving and rationing the food you have left.

Your second statement is literally the Malthusian hypothesis which has been proven wrong repeatedly.

Division of labour is a good thing. It really sucks having to do everything yourself poorly because you don’t have enough time to do it right.