It is true that HDMI 2.1 requires more logic, but one of the annoying parts of the earlier HDMI versions is that a sink needs a PLL that covers a large, continu

It is true that HDMI 2.1 requires more logic, but one of the annoying parts of the earlier HDMI versions is that a sink needs a PLL that covers a large, continuous frequency range. DP and HDMI FRL only need to support a few fixed frequencies, which is much easier for analog designers to design for.