10 fingers/base 10 isn't inherently any more "natural." There are cultures that use(d) base 12 (and count using the 12 finger segments on one hand) and probably

10 fingers/base 10 isn't inherently any more "natural." There are cultures that use(d) base 12 (and count using the 12 finger segments on one hand) and probably others. And base 12 is way more divisible.