Poor lighting in this room, taken w/ an iPhone 12 Mini. Just grabbed the first result of "50% gray screen" from youtube.

I can see some vertical stripes if I look closely, but that seems to be general aging and not burn in. At least I can't think of any images that could have burned in that pattern with what I've used the screen for. Tbh this picture makes it look worse than it appears but you'll just have to take my word on that. ¯\_(ツ)_/¯ This TV has gotten a lot of (ab)use, much more than a typical home I would think.

I'm glad you suggested this test because now I have some fuel for upgrading in 2022. ;) I wouldn't say the aging I can see from this test is noticeable in most cases, but it's a tool I'll use in the future to see how the striping worsens.

I went ahead and ran a pixel test and they're all working fine still. Maybe LG has been cutting costs as their OLED lines have matured? Or it could be bad luck of the draw.