If all HDMI cables are basically the same design, pinout, etc. how have they been able to double, quadruple, etc. the bandwidth on them over time?

Question

Going from HDMI 1.4 to 2.1 there is a 5x increase is bandwidth. Is it because the cables themselves were never the issue but it was the connectors/chips in the devices themselves that couldn’t handle it?

I know part of it is the actual quality of the cables themselves and tighter tolerances, more twists in the wires, material purity, etc. but I can’t imagine that alone would be enough to fully account for this.

In: 565

Answer 1

Piggybacking on the OP, is there a specific reason HDMI cables are usually more stiffer and less malleable than other cables?