I'm not sure it happens, and if it does the results aren't pretty.
In the 1970s, the idea of home computing seemed ridiculous. Even the hobbyists like Woz that wanted computers in their homes weren't thinking much beyond their hobby and other hobbyists; Jobs was the one who saw that these could be people-centric devices and that everybody should have one in their living room.
Even if all Jobs did was market the darn things better than anybody else, that's still indispensable. Without everyday consumers buying computers and pumping billions of dollars into the industry, very little of the last several decades of innovation would have happened.
But he went way beyond that, being intimately involved in every project he ever participated in, bringing a healthy dose of the liberal arts with him - music! typography! color!
Without Jobs… eventually, yes, computers would have probably gotten small and affordable enough to be in peoples' homes. But would anybody have wanted them? Without Jobs, that prospect would have been about as appealing as having your own forklift, cash register, or timecard punch at home. Even if you could, why would you? Look at how terrible the IBM PCjr was -- and they made that thing after they had Apple's people-oriented computers to ape.