The "nor is the hardware a PDP 11". Byte access was the main new feature of the PDP 11 that C adopted. Are you saying being able to access individual bytes is not relevant on modern hardware?
It is, however hardly something unique to C, as the C crowd pretends it to be.
Might more mean that we've standardised on a few things like what a byte even is.
The PDP-11 had both 8 and 9-bit bytes. Thats a complexity that few programmers have to touch on, today.