This is a good read, and is what I've been hearing from my contacts inside Apple for years now. It's really starting to hurt them IMO. This is also why we keep saying that they are extremely unlikely to ever fix the driver bugs.
FWIW, I finally got my iPhone paired with my car (which had been working fine for years on prior iOS versions but which broke immediately after upgrading to 13), but not completely. In order for it to work, I had to pair it as an audio device (not a hands free device). So I can still listen to music/audiobooks and control them from the car's controls, but the phone is still manual. This works for me since I never talk on the phone while driving anyway, but it does just go directly to the quality (or lack thereof) of iOS 13. And this will undoubtedly fall in the category of a non-regression bug in the next OS release (read the article linked above for clarification) so it will also likely never get fixed.