These days they make fridges so light weight that the doors can’t hold as much weight as they used to.
Use the door for small containers of left-overs, bread, celery, peppers and anything else that is not heavy, glass or fluid.
If your fridge is not performing well or you get lots of condensation check to make sure the door is sitting square and level with the rest of the cabinet.
Make sure the door seals tightly with no gaps or air leaks.