This is a bandwidth limitation of HDMI 2.0. Chroma 4:4:4 is generally recommended for PC use, as it helps the text appear clearer. For console gaming, most people won't even see a difference with 4:2:2 unless you are playing a very text-heavy game or using your console to browse the web. You can learn more about Chroma Subsampling here. Game mode is generally the best setting for console gaming, as it will disable most of the TV's post-processing to reduce input lag.