I remember hearing it’s even possible to plug in a USB-A plug too slowly, making the legacy pins make contact first, which results in a 480 Mbps connection – despite the cable, the host, and the device all supporting superspeed!

Can confirm, was victim of this.

Couldn't figure out why my 5-disk USB enclosure was so ungodly slow. Quickly I saw that it was capping suspiciously close to some ~40MB/s constant, so 480Mbps.

lsusb -v confirmed. As it happened I did some maintenance and had to unplug the whole bay.

Since the port was nearly tucked against a wall I had to find the port by touch and insert somewhat slowly in steps (brush finger/cable tip to find port, insert tip at an angle, set straight, push in) but once in place it was easy to unplug and insert fast...

This was driving me "vanilla ice cream breaks car" nuts...

Destroy the whole standard. That's literally insane.

That's the price of strong backwards compatibility. Otherwise, you wouldn't be able to use a USB 3 (superspeed) device on a USB 3 host port with a USB 2 cable at all.

And if you hate this, you should probably never look into these (illegal by the spec, but practically apparently often functional) splitters that separate the USB 2 and 3 path of a USB 3 capable A port so that you can run two devices on them without a hub ;)

What in the world…