To be fair, the designer had people who required walkers (the elderly) in mind. The design hasn't changed in 2 decades. The carts were designed for reliability and ease of maintenance so the supermarkets can do it themselves. Parts haven't changed design, nor do they need to. What has changed is the service life of the batteries and the motors. That cost was passed on to prepackaged foods.  **This is fiction, but its not detached from reality **