Wait, there already are PD-specific cables, video-specific cables, and the like. If your cable is short enough, it's not an issue, but if you want one longer than 1 meter, you will likely have problems with 4k video on a cable that isn't specifically designed for high data rates.
The high speed and power delivery cables have chips on them, so the connected devices won't use high speed or PD if the cable can't handle it, regardless of length.
