You don't have to imagine, just go to any other car (well new ones), quite literally every other major carmaker has Carplay (and Android Auto). Even electric cars. You can see how things are implemented, and yes there isn't deep integration with the car, it's its own world and it doesn't tell you your range or anything. But it doesn't have to, it's focused on music/radio and navigation. You can also mix and match the car system with Carplay, so for instance I can listen to XM radio from the car but have Carplay navigation running side-by-side (sometimes that can be very jank, there have been iOS bugs that kept that from working, mine wanted to play Apple Music and didn't allow the XM radio to go through, but bugs generally get fixed with iOS updates). If you wanted the opposite, car navigation and Carplay music you can do that too.
As I said they can do this like literally every one else, and Carplay's oddities wouldn't go against Tesla because it's up to Apple to fix its issues, but not having Carplay is a mark against Tesla, at least for some people. Take a look at like Mercedes's new system (new S-Class or EQS) or BMW's iDrive 8 (well maybe not for a few months because they will need an update in July for Carplay, ouch). You get a great infotainment system, they offer great maps now. They have built in music like Spotify, etc, but they offer Android Auto and Carplay so people have options.