Nor should we eschew more practical means of generating power--as long as we don't have to.
Oxen, as you point out, aren't particularly efficient engines. I've been wracking my brain for decades to devise a means of making chickens haul their own tractors. Not easy.
Stationary bikes are probably more efficient than oxen, but there's plenty of better ways to make power, and if Megacorp won't play nice, then bye bye Megacorp!
Power is available in so many different forms that it's really not possible to prevent folks from generating it.