What makes the binary system so applicable to computer circuits?

Binary is the simplest way to implement operations and information in a computer system.

However, It is not the only way.

But because of the nature and simplicity to switch electricity on and off it is a natural for computers.

Computers speak only one language which is composed of two sylables, namely "on" and "off". This is just like your light switch on the wall.

Computers are made up of millions of switches. This complexity allows logic functions, similar to human thought, to be performed.

This manifests as a very impressive operation only because a computer operates at such fast speeds.