Just a couple..
First and foremost the RV must be fairly level for the refrigerator to operate properly. Older RV refrigerators required more precise leveling, but even newer models need to be close to level for optimum performance. Over time a cooling unit operated out of level can be permanently damaged
There’s also something to be said for the fact that even if your RV fridge seems to be running sufficiently, that doesn’t mean that it isn’t sustaining some amount of damage that will reduce its operational life over time. Therefore you should try to keep your RV fridge as level as possible at all times.