You can do 4K with way less that a hundred megabits, some PoE cameras don’t even put a gigabit port anymore since it doesn’t need it.

Only with compression. Uncompressed 4k60 is 12.54 Gbit/s, so high data rates are definitely useful for wireless HDMI.

4K can mean a lot of things but some of the low bitrate iterations look fairly average.

Yeah but OP mentioned “webcams”