I’ve never used CarPlay but I thought CP Ultra was a non-starter the first time Apple revealed it.
In the interview with Nilay Patel, Mary Barra said they continue to talk to Apple and Google and, as I recall, was noncommittal when asked about running apps from Apple, etc.
In any event their strategy hasn’t hurt their most recent sales. I recently read that GM just had their best sales year of the past ten and is now the second largest EV manufacturer in the US, behind Tesla.