Feet are slightly more convent for declining human sized things because meters are just a little too big to describe human height and centimeters are a bit you
If you were designing a system to describe humans with no other consideration you’d probably pick one where 10 units was the average human height. And feet is closer to that than meters. Also you can divide 12 by 6 and 3.
I’m not saying that customary is superior just that it does has certain advantages.