USB is good enough for real-time music on iOS and many Android phones. If you want to already snap the controller to the phone, adding a plug isn't much trouble. And some phones still have the 3.5mm jack.
At least the Android version has external USB-C port that could fit an adapter. The specs say only that you can charge through it, it would be nice to know if it's really limited to charging or fully functional.
It is not functional and is power only. Source: I returned mine after being incredibly annoyed by the whole experience because of audio lag. I tried the Razer low-latency earbuds but the latency is still annoyingly high.
I can only imagine the product manager telling HW designers that nobody cares about audio latency, everyone uses Bluetooth anyway and damn this thing must be cheaper and ready for production yesterday.