"Dog’s life is easier than human’s life" is "개팔자가 상팔자"(kae-pal-tcha-ga sang-pal-tcha) in Korean.
The literal translation is the dog's life is better than people.
Idiom "There is also often hard or go live Good luck with work, dog comfortably live go while receiving the care of his master person" to express the human and dog life.