He saw PARC’s version of the mouse and saw what it could be, and turned it (or had engineers and coders) into something more than useable, virtually indispensable.
He saw the potential of OO programming and GUI more than PARC did, and it’s now the cornerstone.
PARC tried to market PC’s on their version, but couldn’t sell them because they were cumbersome and useless.
He saw the potential for the iPhone when no-one else did, and it was copied by all and sundry. He didn’t create the bits and pieces - some of his competitors did - but he conceived of the totality in the way Marconi saw how 5 different pieces of technology could be combined to assemble the radio.
Yeah, he was an ■■■■■■■■ and a lot of people hated him, but they rode his coat-tails to fortunes too.
Funnily enough, he was diametrically opposed to creating a Windows version of iTunes (which wim would have appreciated), but it opened the iPod up to the many millions of owners of Windows machines.