The usual fare of Dongle Incompatibility, we have a Dell USB-C Dongle that won't provide display outputs to anything that's not a specific Latitude Model, we have quite a few HP Notebooks that won't properly charge with standard USB-C Chargers (even Apple ones), then there's the USB-C Audio Adaptor issue where some phones output analog audio via USB-C and others need an active adaptor with a DAC, which look physically identical...

The Standard, if you fully embrace it, is a mess.