Actually, it is the only (display) protocol. HMDI Alt Mode, while specified, never really manifested and is effectively dead. DisplayPort is the only alternativ

Actually, it is the only (display) protocol. HMDI Alt Mode, while specified, never really manifested and is effectively dead. DisplayPort is the only alternative and is more flexible anyway. Its packet-based nature is not relevant for DisplayPort Alt Mode, by the way, because it gets dedicated pins. Sometimes enough for two lanes, sometimes enough for four. It's hilariously consumer-unfriendly. Only Thunderbolt leverages the packet stuff and can transport up to eight lanes worth of DisplayPort. macOS does not support MST. Who is supposed to get this? I don't know.