BT pairing in our Ram works fine, and it works fine with the aftermarket Pioneer radio in my car. I've never had a major issue with either one with any phone I've owned, iPhone or Android.

For our Mazda, though, BT pairing does not work reliably with my Samsung S21 - it's okay for phone calls (in fact, the car "steals" my calls if I'm on the phone at home and my wife gets home with the car), but for music it almost never works correctly, unless I'm also using Android Auto, which is rare because I just don't need it for most day-to-day drives. The BT phone and music works fine for my wife's iPhone, though.

I blame the car - my phone works just fine with several sets of Bluetooth headsets, and the other two car stereos. I think Mazda just didn't bother to do any debugging before they shipped that piece of shit to the dealers. (This theory is based on other bugs we've found in the infotainment system as well.)

Because they do the bare minimum to meet the spec so that they could advertise it then. They still do the bare minimum now.