> so shipping with a chunky cable that doesn’t even carry decent data feels like a bizarre oversight.

USB 2.0 can support up to 480 Mbps. It’s more than fast enough for any audio stream you can send to a DAC.

Your headphones don’t need USB 3.0 5 Gbps speeds. USB 3 requires extra wires with different properties that need to be controlled more tightly, which can impact cable flexibility. If your headphones used USB 3 when they didn’t need it that would be one more thing to break and more failure modes for the cable.

A USB 2 cable with fewer conductors was the right choice for this product. The fact that you only got miffed about it when plugging the cable into a tester, not from actually using the product or cable, is good evidence that a USB 3 cable wasn’t needed.