So my question is how many people are there who have a TV old enough to have no display ports but be of that outrageous specification

As far as I know no consumer TV has Display port.

I bought a TV maybe 2-3 years ago that supports 4K@120 and it doesn’t have a display port, only HDMI.

I’m using a recent 42" LG OLED TV as a large affordable PC monitor in order to support 4K@120Hz+HDR@10bit, which is great for gaming or content creation that can appreciate the screen real estate. Anything in the proper PC Monitor market similarly sized or even slightly smaller costs way more per screen area and feature parity.

Unfortunately such TVs rarely include anything other than HDMI for digital video input, regardless of the growing trend connecting gaming PCs in the living room, like with fiber optic HDMI cables. I actually went with a GPU with more than one HDMI output so I could display to both TVs in the house simultaneously.

Also, having an API as well as a remote to control my monitor is kind of nice. Enough folks are using LG TVs as monitors for this midsize range that there even open source projects to entirely mimic conventional display behaviors:

• https://github.com/JPersson77/LGTVCompanion
• https://github.com/cali-95/LGTVLinuxCompanion

I also kind of like using the TV as simple KVMs with less cables. For example with audio, I can independently control volume and mux output to either speakers or multiple Bluetooth devices from the TV, without having fiddle around with repairing Bluetooth peripherals to each PC or gaming console. That’s particularly nice when swapping from playing games on the PC to watching movies on a Chromecast with a friend over two pairs of headphones, while still keeping the house quite for the family. That kind of KVM functionality and connectivity is still kind of a premium feature for modest priced PC monitors. Of course others find their own use cases for hacking the TV remote APIs:

• https://youtu.be/io_AFseYleE
• https://youtu.be/76wAEJOdBq8