Just because tip of the cable is looking like USB-C, you shouldn't expect it to support HDMI etc.
Most people are not looking for full set of USB-C features. Most people are just looking to charge their device.
I don't remember last time I wired up my phone to my computer for any data transfer, and I am a nerd who reads HN. Think about the average folk.
If we go further, a big chunk of people, don't even use anything like a file manager.
In short, biggest reason we have cables around these days is; To Charge Up. That's it.