HDMI was a mistake.
It's fun how people recommend not to use HDMI cables longer than 7m for a reliable 4K signal. You can buy 20m cables, sure, but the spec doesn't guarantee that it'll work.
My dear, where am I supposed to put the projector and the AV receiver in the living room if there's a <10m cable limit between them?
(My current setup is 1080p and the looong cable works fine. But who knows if a future hardware upgrade will require changing the cables, too.)