Now they're a victim of their own success. All their product lines are relatively successful. There's not a significant product that they can kill (they killed the routers now, but that probably doesn't free up too much focus anyway). I think even Steve would've struggled with this conundrum.
Internally, they've tried to merged Mac and iOS, ala Windows 8/10, to allow them to keep a single focus.. but their conclusion was that it compromises both Mac OS and iOS in a way that they don't want to do. And if they made the merged OS closer to iOS, it would alienate a lot of Mac users and developers.
So how should Apple refocus? Who knows. I think it's a flaw to think that Steve Jobs would have magically solved the problem already. He was smart, but not a god.
> how do you plug your lightning headphones into your Mac?
You don't buy lightning headphones.
Apple will kill the lightning on iPhone too. Either replacing it with USB-C or removing it altogether. This is all part of a transition which is unavoidably awkward.
Apple is betting heavily on wireless, and lightning headphones is just a stop-gap solution while wireless headphones improve. A way for people to be able to buy some cheap, simple headphones to replace the bundled ones if they need to. If you buy an expensive lightning-only headphone you're a fool.
The moment that wireless charging is fast enough to completely replace wired charging, they will kill the lightning port and perhaps bundle a case which bridges lightning or USB-C to wireless charging+bluetooth 5. Third parties will deliver cases with bundled battery, USB-C and 3.5mm jack, and since the phone will be even thinner without any ports, the phone+case will still be plenty thin enough for daily use, and sturdier too. Everyone will be happy (hah, as if..)