I’m sure Apple would if the could. They obviously can’t, though. I can’t imagine that Google would allow them to implement those features. So Google is the holdup. Apple uses Google’s API and is completely dependent on them in what they can do. (Hey, that’s their right. No problem with that. You don’t have to allow your competitor everything.)
That is exactly the reason why Apple has to do it on their own. It might be worse than Google Maps (at least in the beginning or forever), but at least it will allow for progress.
Google has made it very clear that they want to build Google Maps for iOS and provide the same experience as is available on Android. It was, for a long time, an explicit no-no to provide turn-by-turn navigation in an iOS app.
There's no excuse now, though. A top ten app on the store is MotionX Drive, there are even apps by Navigon and TomTom out there too. Google could come along and eat all of their collective lunches if they'd just do it.
No, they still can't because it reproduces functionality of the OS. They could provide just navigation, but if they ported the Google Maps app to iOS, it's very likely that it will be rejected for the same reason that a port of Chrome would.
Port of Chrome would be rejected for completely different reason: Apple disallows downloading and executing dynamic code from internet unless they're executed by Safari's JavaScript engine. This is not the case with Map. There's already a lot of GPS apps with different map data than the one in Maps app.
Can Apple do it in their own app? That’s the relevant question. Third party apps are irrelevant.
Google doesn’t allow third party developers (and that includes Apple, obviously) to offer turn-by-turn navigation. Here are the terms (10.2 c): https://developers.google.com/maps/terms
Letting Google build the maps app is obviously out of the question. That’s a pretty ridiculous idea. Would Google let Apple build a critical piece of Android? Obviously not.
(Also, where has Google made that clear? That’s a serious question. I’m not aware of any such statements from Google, so it would be awesome if you could point me in their direction.)
That is exactly the reason why Apple has to do it on their own. It might be worse than Google Maps (at least in the beginning or forever), but at least it will allow for progress.