Get a big monitor with all the specs you want and connect it to an old laptop. You can watch whatever you want on there. You can even play video games on your Playstation or XBox if it has an HDMI port.
- >= 85"
- VESA mount
- 4K @ 120Hz (or better)
- < $2K
- "infinite" contrast ratio
There are lots of monitors that fit OP's description.
Seriously: Name one counterexample.
Yes, it's only 60Hz, but again, 1 search.