Being a member of the USBIF, I can assure you that USB 3 is a hot mess rivaled only by USB-C which is only a port and not a protocol. Many cables and PC's ports do not support backward compatibility to USB 2/1.1.
Indeed.
FWIW, I think the whole of USB is an awful mess. It started as a cheap-and-cheerful trick to avoid some issues with V24/RS232 ports and has added fiddle opon fiddle and trick upom trick as it's grown.
Also FWIW, the numbers, i.e. 1.0 1.1 2.0 3.0 3.1 3.2 and 4 refer primarily to the protocols.
Then on top of some of those there are also speed specificiers,.
The letters A, B, mini-A, mini-B, mini-AB, micro-A, micro-B, micro-AB, the super-speeds, C and whatever else refer to the connectors.
And some now incorporate Thunderbolt, PCIe and DisplayPort.
And, of course, not everyone implements the protocols properly.
I've wasted quite some time getting around
that particular problem.
Hmm ... I think that turned into a rant. Sorry.