Jobs took a company that was nearly bankrupt and turned it into the world's most valuable company.
Do you truly, in the deepest of your heart, believe that he accomplished that alone?
Of course not. What kind of stupid question is that?
He was a leader. As such his main work was motivating others to accomplish the goals that he and his helpers set out. That's not an easy job and there's a reason that you don't see much of it. Elon Musk probably operates on the same level, Bill Gates also. There's a reason you know these names.
Apple has done nothing since Jobs died. Literally, they have coasted. I could grab the local McDonald's manager and put him in Tim Cook's place and get - at worst - the same result.
The sad thing is that he's screwed up stuff that didn't need screwed up. How hard would it have been to simply do standard upgrades to the MacBook Pro line, for instance? They had years, and the best they could do is remove the top row of keys and most usable external ports. They didn't even upgrade the memory capacity - still stuck at 16GB. I had 16GB in my MBP from a few years ago. Come on.
It's frustrating to see what's happened to the company. I personally could have done a much better job of running it (yes, I'm going there) than Tim Cook. At this point, most products have been damaged (no headphone jack, no usb ports, etc.) with little in return. Worse yet, they believe this damage is somehow better - that progress is being made. They seemingly don't understand the concept of a synergistic ecosystem. Hell, even Microsoft is starting to figure this out.
I have no trouble with the fact that they haven't really rolled out another iPhone-sized project since Jobs died. Those sorts of things come around once in a generation and I don't expect such. But you'd think they could have at least maintained standard upgrade paths for the existing products. They've failed to even do that simple task.
When the stock crashes, it ain't gonna be pretty.