Comment by jsjohnst

> for example I looked up a 2 meter Belkin cable advertised as TB3 and it doesn't carry the DisplayPort channel

It’s not possible (I think?) for a USB-C cable to support TB3 but not DisplayPort. Both are alt modes on the USB protocol and use the same wires for transmission, so it doesn’t make sense to go the extra mile of TB certification and not support DP too when you already have the necessary wires.