There is no real reason we use base ten numbers except that we ran out of fingers at ten and used that as a “round” quantity. Five is a convenient half of ten (and one hand of fingers) for higher but not excessive precision. We could have developed a base eight numerical system if we had four fingers per hand and in that alternate reality, you’d be asking why cooks and chefs cook in base 4 increments.
Because we have ten fingers.
There is no real reason we use base ten numbers except that we ran out of fingers at ten and used that as a “round” quantity. Five is a convenient half of ten (and one hand of fingers) for higher but not excessive precision. We could have developed a base eight numerical system if we had four fingers per hand and in that alternate reality, you’d be asking why cooks and chefs cook in base 4 increments.