If you want extremely good picture quality and also insist on "dumb" the best you can get is a second-hand Pioneer or Panasonic plasma display. I don't think any of these ever had "smart" anything, and their image quality is top notch.
> the best you can get is a second-hand Pioneer or Panasonic plasma display
Indeed, this is what I did. It's 1080p of course but at the size of most plasmas and average sitting distance, 1080p is all you need. (More worried about the lack of HDR.)
The main issue I've had is that the "backlight" (not really a backlight) seems to be significantly brighter for two "bars" on the left and right of the screen about 2-3 inches wide, giving films a odd "banding" look. Also, the black levels are much higher than I originally expected. I've read that Panasonic sets artificially raise the black level over time to prolong the expected life of the TV and that there's a way take the TV apart and reset this internal clock, but I haven't tried that and it seems risky. (I recall plasma sets being advertised as having "infinite contrast", but having seen some OLED TVs in person, I can 100% confirm there's a difference.)
I still have my Pioneer Kuro LX6090 which is/was the most incredible TV at the time. For older, non-remastered content I still prefer it over my LG OLED.
However if you want the very best image quality with 4K HDR Blu-rays then you can't get better than an OLED.
IMHO the best option on the market today for movies are the Panasonic OLED range followed by Sony and LG which are roughly equal (to my eye).
If you want it for gaming as well I would recommend an LG though. While the image processing isn't quite up there with Panasonic or Sony they offer more options and features that next gen consoles will benefit from and let's be real unless you're a professional I very much doubt you will notice the difference between an LG OLED and a Panasonic OLED but you will certainly notice the 1-2 grand price difference and most likely the next-gen console features like VRR :)
I also have a Sony PVM which I have setup for older consoles as games on PS2 and earlier systems look awful on a flat screen (LCD, plasma and OLED) compared to even a mid-range CRT. I managed to pick up the PVM for 'cheap' a few years ago from a media company that was relocating and selling off old equipment from storage. It is also the best way (imho) to watch most VHS content, especially non-professional/camcorder stuff.