That's very true. They may not be able to find a person who's exactly like Jobs but may be close in quality.
When MS promoted Nadella to CEO, Apple should have removed Cook right away to keep up with the shift in thinking and progress. Their biggest mistake was letting Cook stay on board. Nadella may not a Steve Jobs but the man is sharp and understands what is needed to keep Microsoft going and competitive.
I think the difference is that Nadella has the balls to delve into projects such as HoloLens to make a difference and explore new ways while Cook played it safe. You can also feel Tim's personality reflected off the Apple products that seemed "off".
It's his lack of taste and design sense that's hurting Apple, including Jony who is apparently "checked out". I'm a creative myself and I can smell his sense of being burnt out, staying stale.
Jony should have left Apple and gone independent with his work. That way, he could approach any project he wants to get his hands on. Going independent will broaden his horizon while staying in Apple cripples it.
They need to also not let Williams take over as CEO. I sense something going on between him and Cook as if he's hand picked to continue the " Cook Agenda ". Can you smell it? It's almost as if they have secret lives together.