There's no need to once again dwell upon Apple's history and how the company nearly died until his triumphant return more than 10 years after being ousted. The facts speak for themselves.
The iMac, MacBook, iPod, iTunes, iPhone, iPad and the markets that sprang up around those great products all sprang up on Steve Jobs' current watch. The original Mac happened on his previous watch. NeXT, the operating system that Apple bought from Jobs to bring him back to the company, formed the basis of the new Mac OS X.
Look behind every single successful Apple product and you'll see the hand of Steve Jobs.
Of course Jobs didn't actually develop or design the products any more than Henry Ford designed the Model T or the V8 engine. He just demanded that those products be built according to his wish list.
While other IT companies groped around in the dark trying to discover what products the market want, Jobs just went ahead and built the products that he wanted. He left it until later to convince the market that his products - Apple products - were simply way better than anything else.
People of the stature of Jobs don't happen along very often. Although he co-founded Apple with computer whizz Steve Wozniak and Ronald Wayne, Steve Jobs is the only one who stuck with the company. Apple was his dream and his destiny.
Looking at Apple without Jobs is like looking at a headless monster. It has a great mix of well established and early generation products and has succeeded in becoming a major force in the mobile telecoms space, as well as growing its share of the consumer IT space. But no-one has emerged that could conceivably take the place of Jobs as the head of Apple.