Long time ago was
hands the mean to express numbers - hence became 10 the natural
radix for the number system we use today. We could decide to use
other numbers as radix but will usually avoid this.

Computer based at
digital electronic give no choice - a binary system must be
based at 0 / 1 hence radix = 2.

Binary numbers
actually quite effective - with only four fingers at one hand is
your able to count to 15 versus 5 (with five fingers)