[GoblinSlayer]

Everett proposed relativistic interpretation. The measurement happens solely due to physical interaction and is properly contained in light cone. The difference is that the cat has two states: one dead and one alive, when you physically interact with them, your state splits into two, each state sees the respective cat's state, both are real, but the picture is relative. The observation corresponds to not what exists, but to what physical interactions happen, and because these split states don't interact, they don't see each other as if it was a collapse.