He's a good operator, but not a great visionary. I'm not sure whether we'll ever see a new ground breaking product again developed by Apple. Most of the stuff they've been doing since 2012 have been minor iterations on existing stuff.
The original iPod was only possible because one of Apple's suppliers happened to make a 1.8" disk drive. iPhone and iPod were only possible because flash storage, batteries, screens, and mobile processors all got to a point where the original iPhone was (barely) viable as a product. Apple can't just will that the underlying technologies which will make autonomous cars or AR glasses possible come into existence now. They can nudge things a little here and there, but, for the most part, they have to wait just like everybody else.
Regarding Tim Cook: my take on Steve Jobs is that his most recognized success at Apple was creating the best products in the world. His collaborator for this was Jony Ive. But he had another accomplishment that is much less recognized: he put a tremendous amount of energy into building Apple the company. His collaborator for this was Tim Cook.
IMO, while Tim Cook may not be a product visionary, I think he is unrivaled as a business visionary. Calling him merely a "good" operator does the man a tremendous disservice. Nothing about the way Apple operates is typical. Their organizational structure is almost unheard of for a company of their size, they refresh almost their entire product portfolio every year, they release 3 new operating systems every year, they rarely make acquisitions, but when they do, it almost always works out. They have built an utterly dominating advantage in mobile processors. Etc, etc.
As I said elsewhere, this bothers me too. Cook is damn good at what he does, the problem is what he does is product delivery, not product development. The solitary new line they've launched since Job's passing was new sizes of iPhones and iPads, and the only entirely new product was the Watch, which arguably the first gen (Series 0 now) should never have left Cupertino. It wasn't ready, and I'm sorry but I think Jobs would've told them to take it back to the lab and make it GOOD before they released it.
Much hay is made out of the fact that version 1 of the watch wasn't 100% spot on. But again, that's fine. No company in the world is as good at Apple at iterating on products. So they iterated and the watch is a pretty great product now (and they sold a bunch of version 1 despite it's shortcomings).
The watch, which has been the only product released since Jobs his passing (and I'm definitely not a Jobs fanboy) is.. garbage imo. I'll take my mechanical watch any day of the week, thanks.
1) Lots of people are buying them.
2) They have incredible customer satisfaction numbers. Higher than any other Apple product, I believe.