So you’re saying one hp = one DAY of horse power. How is that even a measurement?

because thats the expected constant power output from a horse given the timespan of about a day (the average human utility time span also)

This is like saying that a bullet upon impact imparts infinite kinetic energy because the time window in which it's measured is literally 0 seconds.

Also if we happen to extrapolate the horse power metric, it's the most power you could utilize from a horse, long term, forever, assuming you wanted to.

This is like saying that you never need to change the oil in your car, because you can just ignore the rest of the miles on it that are outside of the service window.

The unit is literally measuring "what is the theoretical maximum on the possible amount of work that a horse can exude in a continual fashion" considering that engines quite literally, do not care about taking breaks, this makes logical sense. Since the obvious selling point of an engine would be "you don't need to feed it, it doesn't get angry, and it won't kill you if you look at it weirdly, plus it just runs forever, assuming you have the gas."