Luka needs to lean into his defensive style more. He gets too caught up in trying to attack first when his entire style is to let the opponent attack until he gets a sure winning ball. His bat/rubber combo doesn't have enough power to win an attacking rally and he keeps getting into those. If he had a good coach they would tell him to get as many "easy" points as possible, and only attack first as a last result.
Very simple, in China they don't care whether or not you have a childhood, from a young age promising prospects are taken into sports schools where from approximately six years old they start training you for the olympics - that is the main difference between the rest of the world and China. While you are eating sand at the playground with your friends they are doing forehand loops.