Screen burning is not about the black spots. Bright and especially white colored pixel for long time use can make burn in OLED screens, in long term of course.
Maybe I used the term burn in in a misleading way. The OLEDs over their lifetime get dimmer. If this happens for a long time to the same subpixels, it‘s known as burn in.
Theoretically i play random, constantly changing noise to the display and let it display that for a year and them go use it for something else without noticing a burn in since it‘s burned in evenly over the whole screen.
But it still would be more dimm than the screen was before doing this.
Now if i were to play this random noise only on let‘s say the right half of the screen and the left side of the screen stays of/black for this experiment.
You would notice the right half being more dimm over time while the left one stays as good as new.
Now tell me the difference between that second experiment and a phone running youtube in 16:9 on an oled screen that is wider than that with black boarders. Except of course that in this case the affected area is the whole screen except those boarders. Also one could say „But YT isn‘t random noise“, well over the time it takes to burn in a screen you couldn‘t really differentiate between randomness and youtube except if you‘re watching the same „Best Bass Songs of 2019“ compilation with a still background for the whole 3:07:53 of the video.
TL;DR: I should have stated in my original comment that i ment UNEVEN screen burn in. The Screen still get‘s burned in but you wouldn‘t notice it since it gets evenly burned in.
EDIT: I should have mentioned that this happened to me back in the day when i was using my Galaxy Note 8. It was unevenly burned it because of youtubes black boarders back in the day. Ambient Mode would have reduced that to an extent where it probably wouldn‘t have been noticeable. I wish i still had that phone so i could post a picture of what i‘m talking about.
New feature from YouTube. Turn off ambient mode and it should fix itself.
I wouldn‘t turn ambient mode off since it helps to prevent screen burn in
Screen burning is not about the black spots. Bright and especially white colored pixel for long time use can make burn in OLED screens, in long term of course.
Maybe I used the term burn in in a misleading way. The OLEDs over their lifetime get dimmer. If this happens for a long time to the same subpixels, it‘s known as burn in. Theoretically i play random, constantly changing noise to the display and let it display that for a year and them go use it for something else without noticing a burn in since it‘s burned in evenly over the whole screen. But it still would be more dimm than the screen was before doing this. Now if i were to play this random noise only on let‘s say the right half of the screen and the left side of the screen stays of/black for this experiment. You would notice the right half being more dimm over time while the left one stays as good as new. Now tell me the difference between that second experiment and a phone running youtube in 16:9 on an oled screen that is wider than that with black boarders. Except of course that in this case the affected area is the whole screen except those boarders. Also one could say „But YT isn‘t random noise“, well over the time it takes to burn in a screen you couldn‘t really differentiate between randomness and youtube except if you‘re watching the same „Best Bass Songs of 2019“ compilation with a still background for the whole 3:07:53 of the video. TL;DR: I should have stated in my original comment that i ment UNEVEN screen burn in. The Screen still get‘s burned in but you wouldn‘t notice it since it gets evenly burned in. EDIT: I should have mentioned that this happened to me back in the day when i was using my Galaxy Note 8. It was unevenly burned it because of youtubes black boarders back in the day. Ambient Mode would have reduced that to an extent where it probably wouldn‘t have been noticeable. I wish i still had that phone so i could post a picture of what i‘m talking about.
The ambient mode is far too dim to make any noticeable difference in making OLED wear more even