I seem to recall that back in the early days of USB, the organization would hold a conference where all the vendors brought their devices, and everyone would go around testing compatibility with everyone else's devices. Often by making the most convoluted device configuration tree possible (because that's what the users would do).

Myself, I ran into an incompatibility for the first time ever last week in over 24 years of using USB devices. A new Thinkpad with Windows 10 would lock up it's USB bus if I plugged a USB speaker in using the hub on my Dell monitor. Hooking it up directly worked fine. These are all "legacy" USB 3.0 devices with Type A and Type B connectors, and have worked for years with other computers (PC + Mac). What a shitshow USB has become.