It works exactly like having a Mac/PC and a phone.
Right. It's now
two devices to manage (car and phone) instead of a single one (just your phone, which treats the car like a second monitor)
Now I'd have to manage credentials on two different devices. Change my Spotify password? Two places to update it. Etc. And now I've got credentials stored in my car? That's a security situation to worry about in case of breakin/theft.
It also totally kills the use case of letting multiple passengers simply plug their phones into the car's head unit. Might have my phone, my wife's phone, or the passengers' phones plugged into the head unit depending on who's doing the navigating and who's doing the DJ'ing. Now thanks to GM instead of simply swapping the cable, I guess we can take turns signing in and out of a bunch of different apps? lol, nooooooo thanks.
I thought auto makers were finally wising up about a couple of things. One, it looks like they're finally slowly coming back around to physical controls where it makes sense.
Two, I thought they were giving up on the idea of their own bespoke entertainment solutions in favor of giving people what they actually want, which is Airplay/Android Auto. People don't want another device to manage. They just want to plug their freaking phone in.
Normally I wouldn't be irritated; I'd be happy to let the market vote. But cars are complicated beasts these days and there's an awful lot of functionality to demo and digest when shopping. There are a lot of auto features that aren't obviously terrible or obviously amazing; they only reveal themselves as such after you've lived with them for a little while.