I watched a video where two guys who didn't know were shown 4k OLED LG and 8K QLED Samsung with the same feeds.
They figured out the OLED from the thinness of the frame, but they had no idea the 8k QLED was 8K and chose the 4K OLED overall for it's contrast and color, and thought the two sets were comparable for detail, even walking right up to the screens to look at the pixels.