I can kinda, just about, see a use case where basically having a walking security camera would act as a deterrant - you know known shoplifting and pickpocketing areas. Same as an officer walking by will cause a pickpocket to leave the area. Not because they are actually afraid of being caught in the act, but because if they're seen in the area it will cast suspicion on them. Just easier to leave and work elsewhere.
I can also see it for controlling airport parking and stopping people parking in emergency areas, which happens at every major airport.
But apart from those 2 use cases, I'm really not seeing much benefit. And since you can get some low paid security guard to do those roles (do not need actual cops for that). Is the cost really so much cheaper for a robot? I suppose it doesnt need food and toilet breaks (whats the equivalent for a charging break?), and is less likely to accept a backhander to let a scrote go, but it still seems a solution looking for a problem...