They did use USB-C, on the battery itself. You literally can use the headset, and most do, with it plugged in. The exception is when you’re doing room scale, immersive VR, or when you’re walking around the house or office,but that’s generally within the time life of the battery. The connecter on the headset itself is flat with a lock, so that the cord runs towards the back of your head and doesn’t disconnect by mistake. Similar to MagSafe, it is well designed. Last I checked, daisychaining batteries is exactly how the Meta Quest does it with the elite strap, and also how all iPhones and iPads work, so I’m not sure what the problem is.