Individual smartphone manufacturers can implement full audio class specifications on top of Android’s default and many do. In fact, Google supports all three of the USB Audio Classes with the Pixel 2. However, this leads consumers not knowing what to expect from their handsets. You can find forums full of users struggling to understand why products don’t work with their specific smartphone, along with headache-inducing workarounds requiring specific apps and USB OTG cables.

https://www.soundguys.com/android-usb-audio-class-3-0-18494/