Replacing five cables with one is a straightforwardly good change and I do not want to be churlish about it. Anyone who has wired a home cinema with component video and separate audio knows how much of that was pointless.
What is new, and what almost nobody discusses, is that this is the first consumer cable standard containing a mechanism for deciding not to work.
Before any picture appears, the two devices at either end conduct an exchange. The source asks the display to identify itself and prove it is authorised, keys are checked, and only then does content flow. Copy protection is not carried alongside the signal. It is a precondition of the signal existing.
The consequence is a failure mode nobody had encountered before. Two working devices, a good cable, everything powered, and a black screen. No error, no explanation, nothing to diagnose, because from the equipment’s point of view it is functioning exactly as designed by refusing.
It goes wrong in ordinary ways. Switch inputs in the wrong order and the exchange does not complete. Put a receiver in the middle and it may not pass authorisation through correctly. Use a device that was fine last year with a display bought this year, and one end may not accept the other. The standard advice, unplug everything and reconnect in a specific sequence, is what people say when nobody can explain the fault.
Consider who this inconveniences. Somebody who bought a film legitimately, on a licensed disc, playing it on equipment they own, in their own house. That is the entire population affected, because anyone circumventing the protection removed it at the file stage and is playing something that never negotiates anything.
So the mechanism imposes a real cost on paying customers and approximately none on the behaviour it exists to prevent, which is the same conclusion the music business reached about restricted downloads after eight years of insisting otherwise.
The single cable is still worth having. It is worth noticing what came attached to it, and that a generation of equipment now treats permission as a prerequisite for showing you a picture.