… some devices … equipped with USB C, but refuse to work unless the other end of the cable is USB A?
I have at least 4 devices like this at the moment, including a handheld emulator. …
Have you tested each of those four devices with several well regarded/rated USB-C chargers and similarly qualified USB-C to USB-C cables?
Some (nominally) USB-C cables and some USB-C chargers are not capable of _all_ the various output modes and end-to-end protocols that the USB-C world includes.
Even some of the earlier model USB-C power adapters from Apple were limited spec. Apple did list all the modes they actually implemented in each charger model if one were to go look.
It would not surprise me to learn that various adapters and cables currently in the market are only implementing portions of the USB-C spec.
It would be interesting to learn whether the four devices you mention will work with _any_ USB-A to USB-C cable or only some.
Edit: Also, in some cases the USB-C connector must be oriented one way up. If connected with the other side up, the USB-A internal connection does not work. Sometimes I encounter this and have to ‘flip’ one end of the USB-C plug over, plug it back in, see if it works. Sometimes I have had to do this on the other end or even swap the USB-C cable end for end.
USB-C (and ThunderBolt) continues to impress with the amount of potential and actual user confusion. One connector to confuse us all!