The problem with Bluetooth is the stack is too complex. Too many application-specific profiles baked directly into the protocol, which in turn need to be dealt

The problem with Bluetooth is the stack is too complex. Too many application-specific profiles baked directly into the protocol, which in turn need to be dealt with by device manufacturers. Bluetooth basically handles everything from OSI Layer 1 through 6 at the same time. See: https://en.wikipedia.org/wiki/List_of_Bluetooth_profiles https://en.wikipedia.org/wiki/List_of_Bluetooth_profiles Add to that great complexity at Layer 1, and constantly changing specs. Bluetooth 1, 2, and 4 are all radically different than each other. Compare with WiFi, which only has to do one thing (Layer 1-2). Cellular is much more complex, but that's why releasing a new phone involves endless rounds of (usually mandatory and very strict) carrier certification.