Earlier quoted context omitted.
Sure... if you want to pay twice as much as the similar sized TV.[1] I actually just buy 4k TVs and use them as computer monitors instead. As long as you research to find one that has low response times (rtings.com helps with that), it works fine. 1: https://www.vizio.com/tvs/v405g9.html
Yeah another person brought up that the cost is reduced based on the data their mining for usage. I'd also like to point out that most of the sub-$400 Smart TVs on Amazon don't have any DisplayPorts, and the display is probably of a lower quality than something that's designed to be looked at from a couple of feet away rather than dozens of feet. Bigger than 42", I'd just recommend a projector.
What's the main benefit of DisplayPort when most new hardware supports Hdmi 2.0, which does 4k at 60Hz?
How would you define lower quality based on viewing distance? What metrics are we going by that we might expect to be worse? There probably are some, but I can't think of any off the top of my head.
Reaponse time is the one that comes to mind, not because of viewing distance but because of different intended use cases, but I specifically account for that when looking for a TV to use as a monitor.