Literally the second sentence in your own source:
The designation C refers only to the connector’s physical configuration or form factor and should not be confused with the connector’s specific capabilities, which are designated by its transfer specifications (such as USB 3.2).
He’s right though?
USB-C does NOT in any way specify capabilities or transfer specifications. It only specifies the form factor of the plug.
The plug can be used for any number of things from USB2.0 or ThunderBolt4, to power transfer, hells, even things like analog audio can use the plug.
That’s because da red wunz go fasta. Requires extra points to buy, more spensive.
Fun fact: Apple was part of the group that designed USB-C