Why is the computer important nowadays?

Nowadays, everything is either designed by computer, tested by computer, run by computer, the list is growing every day. Modern planes, cars, ships and trains are either entirely or partially controlled or monitored by computers. Even the humble fridge has probably got a computer chip somewhere in its innards! Whenever a busy office's computer system/network goes down, panic ensues! That is how dependent modern life has become on a tiny piece of silicon!