"Over time, this shaped a deep biological aversion to unnecessary exertion." This is both ahistorical - dancing and athletic competition are effectively human universals - and abiological - wild animals play.
No one is playing a game of soccer and thinking "i could just build a robot to do this and avoid soccer". People spend hours training for marathons, ironman events etc, just because they want to.
Imagine any job paid as much as software. What would you do? For many of us the answer would be far more labor intensive - I prefer construction a million iin times over software, but software pays a million times better.
So our economic system coerces us into these sort of broadly sedentary behaviors, because that's where the money is.
That said, this argument when applied to humans is nonsense. We are highly energetic endotherms. Our bodies require exercise for a huge list of well supported reasons