A USB-C port that only supports USB2 data and power only needs a few resistors across some pins to trigger legacy modes and disable high current/voltage operation. All the extra bits are the things that jack up the cost.
USB3 and altmodes require extra signal lines and tolerances in the cable.
High-voltage/current requires PD negotiation (over the CC pins AFAIK)
Data and power role swaps require muxes and dual-role controllers.
That's all the stuff that makes USB-C a pain in the ass, and it's all the sort of thing RPi Nanos don't support.
You're confusing USB C and USB 3.1+. USB C is just the physical spec. You can design a cheap device that will only support USB 2 if you just connect ground, Vbus, D+ and D- and gasp add two resistors. It will work just as well as the micro-usb plug.
completely valid, but i would like to think the org is still designing for accessibility for newbies in mind.
like you said, the connector does not have to follow the standards. i have seen hdmi ports being used to carry pcie signal (not a good like but here is one such device https://pipci.jeffgeerling.com/cards_adapter/pce164p-no6-ver...) amgon other things. it is still non-standard behaviour.