i still don't see how this is intentionally obtuse, feet are a mid point between inches and yards, it just makes sense to break down things over a certain amount to a much more palatable scale. Everyone knows roughly what 1 ft is, and everyone knows roughly what 1 inch is. Paired together you can get a pretty rough and accurate guesstimate of height. I feel like it's also pretty expected for it to be within the range of 4-6 ft. Most people don't really measure feet outside of that range, unless you're doing construction.

humans are a comparatively arbitrary height so i feel like you're just complaining about the height of humans being weirdly arbitrary? Out of all the systems you could use for height, ft and in is pretty well tuned to the human nature, you're not gonna do much better.