From the photos, this looks like a Lightning cable, not a USB cable.

They're referring to the USB protocol, which lightning uses.

Can't wait for the consumer keyboard that saves everything that was typed to it and/or executes things on its own

usb keyloggers have existed since just after USB came out, and badusb is totally a thing.

They have, but all of them are "personalized" attacks - as in, a malicious person needs to install these on specifically your computer, without your knowledge. What I was talking about is some kind of device from some noname Chinese manufacturer that presents as harmless, but actually sends off some additional data back home

Yeah, it was sold to schools in the 90s.

https://en.wikipedia.org/wiki/AlphaSmart

Oh yeah, I remember reading about the AlphaSmart somewhere! Though it is quite different from an ordinary-keyboard-looking spying device that I tried to describe in my original comment. The AlphaSmart feels like more of a digital typewriter that just had a really primitive data transfer method

Not at all.

Usbc is just the connector.

Running display port graphics over usbc is no less safe than using a bigger display port connector.

Can a rogue displayport peripheral present as a storage device, keyboard, etc?

Answer is "it depends".

USB-C always has a usb2 channel available, then 4 lanes that can be display port or thunderbolt or usb2/3 or whatever else.

This is why most android phones have options for USB including "charge only".

Right but a normal DisplayPort or Mini DisplayPort connector doesn’t have USB…