I don't know who needs to know this but it's something that has been handy in the past for me. You can totally use wireshark on USB interfaces, I've used it to try to reverse engineer proprietary protocols over USB https://wiki.wireshark.org/CaptureSetup/USB
CaptureSetup/USB - Wireshark Wiki

@joew I found out about this when I wrote a network link layer thing over usb (can't remember the details now) and reached for the first network debugging tool I knew, and was relieved to find it worked with usb too!