Yes, it is necessary, especially since objects get stuck in the backpack and once they get jammed in there, Zoi is unable to pull them out. This should be an emergency option available to the player. Right now my Zoi’s backpack is a black hole. If something falls in there, you can only throw it away or sell it. Unfortunately, they automatically put various items in there. I’ve already reported this as a bug.
Bug with items stored in backpack in backpack - Bug Reports - inZOI Forums