@翠星石 @Eric Zhang >most
factually inaccurate, the USB C ports on most phones are connected to their motherboards via flex cables (cables are hardware) that only have enough conductors to enable USB 2 mode connections 

 @2eaaf069 Yes, note the part where I noted: "or the USB-C port isn't wired up correctly".

Signal integrity over flex cables isn't that great, but they will carry a 1080p DisplayPort signal just fine.