Most OEM infotainment sucks, and it's taken a while for things to improve. I'd be willing to say your older car has a resistive touchscreen and physically couldn't support multitouch
CarPlay is definitely an improvement if you're comparing it to something like Ford Sync for example
This wouldn't be a solution to the argument in the article: Rivian and Tesla don't want to support phones projecting to infotainment
As it is, CarPlay is implemented as a h264 video stream which receives touch, microphone, and metadata from the vehicle, the protocol is fine albeit proprietary
CarPlay is definitely an improvement if you're comparing it to something like Ford Sync for example