The headphones have equivalent performance whether a USB 2 cable is connected, or a USB 3 cable is connected. The headphones themselves are not USB 3 devices; the addition of USB 3 cabling instead of USB 2 cabling would change absolutely nothing about how they work.

So, no: I wouldn't expect the cable for a pair of headphones (of any price) to support USB 3. That represents extra complexity (literally more wires inside) that is totally irrelevant for the product the cable was sold with. (The cables included with >$1k iPhones don't support USB 3, either.)

Meanwhile: Fast charging. All correctly-made USB C cables support at least 3 amps worth of 20 volts, or 60 Watts. This isn't an added-cost feature; it's just what the bare minimum no-emarker-inside specification requires. A 25-cent USB C-to-C cable from Temu either supports 60W of USB PD, or it is broken and defiant of USB-IF's specifications.

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Now, of course: The cable could be thinner and more flexible and do these same things. That'd probably be preferred, even: Traditional analog headphones often used very deliberately thin cables with interesting construction (like using Litz wire to reduce the amount of internal plastic insulation) to improve the user's freedom of movement, and help prevent mechanical noise from the cables dragging across clothes and such from being telegraphed to the user's ears.

Using practical cabling was something that headphone makers strived to be good at doing. I'm a little bit annoyed to learn that a once-prestigious company like B&W is shipping cables with headphones that are the antithesis of what practical headphone cables should be.

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But yeah, both USB C cables and the ports on devices could be better marked so we know WTF they do, to limit the amount of presumption required in the real world. So that a person can tell -- at a glance! -- what charging modes a device accepts or provides, or whether it supports video, or whether it is USB 2 or USB 3, or [...].

Prior to USB C, someone familiar with the tech could look at a device or a cable and generally succeed at visually discerning its function, but that's broadly gone with USB C. What we have instead is just an oblong hole that looks like all of the other oblong holes do.

After complaining about this occasionally since the appearance of USB C a decade or so ago, I've come to realize that most people just don't care about this -- at all. Not even a little bit. Even though these things get used by common people every day, the details are completely out of the scope of their thought processes.

It doesn't have to be this way, but it's not going to change: Unmarked ports are connected together with unmarked cables and thus unknown common capabilities are just how we roll.