Yes, the OP quote ignores that both horses and cars are controlled by (added this word in edit) people. Also, there are still places where horses are better. I would rather take a horse and some oats out into a field in Montana, than a 4-wheeler, gas, a spare tire, a winch, and whatever else I needed to be sure that 4-wheeler didn’t up stuck somewhere, miles from anything.
I don’t think replacing labor is the problem, it’s how we delegate thinking. We have learned to create more food with fewer people, but we still treat the labor of farming pretty much the same. just one example