I didn't know about the AVCTP, but I completely agree on the possible alternatives Bluetooth could use.

From what I've read in the last few days researching to write the post, it feels like Bluetooth was designed under some constraints 20 years ago, and it keeps using the same constraints.

For example, it's unreal to me that the bandwidth for a Bluetooth connection is around 3 Mbps when we've had 4G with 100 Mbps for over 10 years, let alone 5G at 20Gbps.

And yes, the codecs in the firmware is really bad, although very convenient for the companies selling devices I guess. There aren't enough incentives there for the change.