CarPlay mostly works, and although it has issues it's definitely user-focused. CarPlay doesn't prevent car makers from tracking vehicle activity. In the end, consumers don't give a shit about the in-vehicle infotainment. It sucks, or it's AA/CarPlay. The first generation of iDrive showed that rich people people will buy cars in spite of the in-car stuff. In fact, most car infotainment sucks, yet people still buy cars…
I think a key thing to consider is that there are in fact three separate questions at play here:
1 - Does infotainment/software UI differentiation matter in the car market? Is there a significant enough market advantage for having better UI that anyone should care?
2 - If there is an advantage for better UI, is it enough of an edge that would compel you to build your own? Or is it the case where it simply has to be good enough?
3 - If there is enough differentiation to be worth building your own, is your company good enough at software to pull it off?
Personally I think the answer to #1 is YES. I think cars with better UIs - while not sufficient in and of itself - have a market advantage.
Where car makers start veering off from each other is the answer to #2. If you believe that you just need a "good enough" experience to not be actively awful, then you buy off-the-shelf. You see this with Volvo/Polestar and Google Automotive. The "skin" around the stock experience is minimal at best, with only minor customizations.
If you believe that being excellent at it confers some advantage, you'd try to roll your own. This would include folks like BMW and Mercedes-Benz.
Now, where the latter strategy really goes off the rails is question #3. That said, if you believe the answer to the first two questions compels you to roll your own - would you easily surrender to a third-party? Or would you at least try to level up your software orgs to make a serious play?