I don't own a Tesla.

I have rented one though, so I know enough about the software experience to know that there's (currently) only one reason why I might wish for CarPlay over the integrated software experience, and that's Waze. Maybe.

I own two (petrol) cars. One has CarPlay, the other has a rigid phone mount between the steering wheel and centre console. While I appreciate the former for its nice large widescreen map, I still prefer the latter. Waze in CarPlay mode (due to the restrictions on what can be shown on the phone screen) is simply more annoying to operate. So if was in the market for a Tesla, and I had the choice between CarPlay support or a nice phone mount between the centre console and steering wheel, I'd probably choose the latter.

(I would still campaign for Tesla to support CarPlay, because why not.)