Not sure where you're getting those requirements. OP said 60-80 inches, 4k with at least 60hz, and they said "I don’t mind paying a premium". They also never mentioned a VESA mount or "infinite" contrast ratio.
There are lots of monitors that fit OP's description.
There are a dozen TVs at any decent big box store that meet those specs, and roughly zero monitors, even if you look online.
Seriously: Name one counterexample.