And there's also Power over Ethernet, which comes in multiple standards and several mutually-incompatible non-standard variants. And non-Ethernet systems that use the same 8p8c connector. It's still a matrix.
I’d argue that people who even know about PoE are a small number whose job depends on them understanding such intricacies (and even them can get it wrong, as proven by this very thread). USB is mass-market consumer technology and has to be simpler than that if it wants to succeed. The best we can hope for, as I mentioned in another post, is something similar to washing labels.
