As long as the stock infotainment system has everything I need, I don't care about CarPlay/Android Auto.
The default infotainment in my Tesla gives me:
Apple Music
YouTube Music (via Bluetooth)
Navigation with integrated charging stops
Contacts
Hands-free text messaging
Calendar integration
And when I'm parked (like when I'm waiting for the kids in carpool), I can watch Disney Plus, YouTube, Plex, etc., on the big screen (also handy when charging on long trips).
If GM or whatever other company can give me all that, I'd probably be fine with their implementation.
Now in my old 2017 Audi A4, CarPlay was a must because the default infotainment/navigation was absolute TRASH.