

In addition to what the other commented said, a lot of sys and net admins really don’t like the idea of every lan device being globally addressable, while there’s ways around it, a standard ipv4 Nat is a safety blanket to a lot of admins… Not that it should be like that, just my observation.
PS2 keyboards use interrupts rather than polling in USB, meaning every time a key is pressed the CPU stops what its doing to process it.