Japanese dramas, Korean dramas and Thai dramas seem to be obvious just by looking at the picture quality. Why is the difference so big? What caused this difference?

When the Korean drama we watched was broadcast in Korea, the TV signal received by Korean families was already 1080p high-definition signal. South Korea has popularized high-definition film sources, so the picture quality is good. Should Japan do the same? I always feel that Japanese dramas have always pursued the dreamy feeling of pictures, so making TV dramas, whether Korean or Japanese, is harsh and meticulous, and always hazy. A scene can't be compared with a drama. They will take pains to shoot all the facial expressions of actors from different angles over and over again. They will take pains to shoot them over and over again. After several hours of editing, they will eventually appear in front of the audience, only for a few minutes or even a minute or two. Otherwise, actors can't shoot two episodes 24 hours a week, and sometimes they can't shoot one episode a week. This has something to do with the screenwriter. It is precisely because of this that the script will be constantly revised according to the audience's reaction to the characters' preferences.