Really, everything I watch on the TV is fed to it by another device. I don't need or want a smart TV. I just need it to display the picture. It does seem like one could look into just using a plain monitor for this, since that's all you need now.
Most TVs have quite advanced image and motion enhancement filters that have no use in a computer monitor but make a very visible difference in picture quality. I would guess scaling signals is also looked on more closely on a TV set. If your devices already do enough in this directions it is still somewhat hard to use as you have to find a way to turn the TV on. CEC is most likely not present and the only way to control it and the way its done on computers is not understood by most devices.
Those filters are essentially useless garbage that exist for the purpose of attracting potential buyers on a show floor. If the filters were actually desirable, most could be applied at the content level.
Why do these filters have no place on a computer monitor, but do on a TV? If you ever watch videos on the computer screen, logically it would either also benefit from such filters or they are unnecessary anywhere. What makes the TV special?
It does seem to me like these filters could and should simply be ordinary software, not firmware that is baked into the screen.
The difference is that a TV is intended to be used to watch movies, TV shows etc. (which is why they do these effects in firmware) although a lot of TVs have a "Game mode" or something similar which disables these effects. Computer monitors are used for a lot of things (so - generic usage), and these effects would usually end up being terrible or unnecessary for the experience (do you really need motion enhancement filters for text editing, web browsing or spreadsheets?). If you need to show a video on monitor you can just process the image on the GPU and show it on a monitor, which is exactly how it's done.
These effects add a lot of latency (several pictures) so they are no good for general purpose computing, specifically gaming (hence the "game" or "PC" mode on the TV).
I basically agree with everything you wrote. I was responding to a comment arguing that not having such features built-in in plain monitors is one of the reasons that replacing a smart TV with a (video rendering device, plain monitor) combo was impractical.
Agreed, most of these filters have no place on a TV, and a lot of talk about quality difference between televisions is that quality is judged as bad if these filters are on, and crisp if they aren't.
I suspect the point is that all this image processing adds latency, which is fine when you're watching a movie but not when you're doing something interactive. Same reason I understand these TVs have a "game mode" that disables the fancies to keep latency down.
