I'm surprised that nobody has done Ethernet through the USB-C.
(Actually, more seriously, I'm genuinely surprised that nobody's come up with an alternative smaller Ethernet jack that fits on the knife-edge of a modern laptop.)
first PCMCIA connectivity I bought wasn't even for my own laptop
it was a modem card for my spouse's PowerBook or something of that era
I don't remember using it much though. I think I just felt better knowing I could connect it to something else.
(might have foundered on getting drivers installed, as one does. This is the advantage of factory-installed ports: In principle there exists some configuration that works.)
super sekrit club