The variety of what is "supported" is also why it's taken years for USB-C to see any modicum of use outside mobile phone chargers that required the higher power and data rates. It's still not commonplace.
And it's still only useful for low power devices.
Ok, sarcasm aside. Technicaly you dont need separate plugs for different connection levels and power transmission up to certain powers. Initial data exchange at some base speed and minimum power requirements can provide necesarry information for devices to establish or refuse connection