Cook predecessor had a 30 year long career where he came out with essentially 2 ideas, computers for everyone and a smartphone with a user interface good enough that anyone could use it. More than 20 years passed between the 2.....
That's a bit of an oversimplification. Are you forgetting about the ITMS. Talking about disruptive there, at a time when Napster, etc. were reigning supreme, and the labels were crying the blues and bombarding congress to save them from extinction, Steve's ITMS (besides doing very well for Apple) pretty much saved the day for the record companies.
And what about the staggering success of the App store after the introduction of the iPhone.
You also didn't mention the introduction of the iPad, again at a time when inadequate and hamstrung NetBooks were a (short-lived) thing.
Then there were perhaps less dramatic, but no less notable improvements such as 2008's unibody laptops carved out of a one-piece extruded block of aluminum. An idea poo-pood at the time by critics as too labor intensive, unworkable on a large scale, and simply too expensive to continue offering after Apple "saw the light" on that one. Actually a brilliant idea that solved several problems at once. Aside from, as a metal, being relatively light, much more rigid bodies in view of the trend towards ever thinner enclosures, generally stronger laptops with fewer parts that could eventually loosen and rattle, easier incorporation of the higher-capacity terraced batteries, and most importantly, with the thermal properties of Al, greatly improved cooling for increasingly heat producing CPUs and GPUs, with the entire laptop basically one giant heatsink. Btw, the thermal aspect an idea also used for desktops and the Mini, but sadly not for the Time Capsule, an enclosure incorporating both a heat producing PSU and a heat sensitive enterprise class HDD.
Anecdotally, Steve was said to have confided in Walt Mossberg who was at the WSJ at the time, that in his mind he finally had cracked the pesky TV problem, in his quest to also disrupt that dinosaurian industry. Whether Steve actually confided any concrete details of that plan to anyone at Apple, or documented them for his successors is doubtful however, considering the current and arguably increasingly fragmented state of that industry, and how we continue to consume our media. We will probably never know the answer to that question.
I'm sure I've missed some things such as Steve's intended inroads into the educational arena, but on the whole, the restless and perfectionist visionary Steve seemed to have a new area of interest to foist upon us every three or four years since his return in the late nineties.
Not in any way knocking Tim's performance, which under the circumstances has been excellent with the company having risen to stellar heights, but merely expressing an opinion that in the absence of a new visionary, the company will be increasingly hard-pressed in the coming decades to maintain its current perch at the top.