That’s because it generally works. I can connect my Librem 5 to several Bluetooth devices I have around in here and it works flawlessly. Some people complained about audio stuttering with some devices, but not being able to connect at all is uncommon, so you’ll have to investigate what’s different in your particular setup.
Does your car’s audio work with GNU/Linux laptops? Perhaps there’s a difference in compatibility between PulseAudio and PipeWire? Check it out.