Except that I do have experience with both, owned several vehicles with CarPlay, and have since replaced them all with Teslas.
That should tell you which I prefer.
CarPlay is designed to solve a problem Tesla doesn't have ... namely, that legacy automakers are NOT software companies. They're assemblers - they buy units from third parties and make them work together.
CarPlay brings a unified interface to an in-car display. That's not a bad thing in theory. In practice, I found CarPlay clunky and limiting. In a big way.
My biggest problem with CarPlay is its limitations on lists and scrolling. That's just ridiculous - not allowing me to see my own data is ridiculous.
Specifically, things like lists of albums, or Sirius XM stations, or even lists of nearby restaurants. All of that is limited by CarPlay and makes it unusable.
But yes, I have plenty of experience with both CarPlay and Tesla's interface. There's *plenty* not to like about Tesla's, but I'll still take it 20 out of 10 times over CarPlay.