It is solvable, typically by city government. No doubt if there are sufficient people annoyed by discarded scooters overcrowding the sidewalks then the city will be compelled to act. The city may designate specific zones for such discarded conveyance, or they may designate zones that are to remain free of such. They may choose to redirect police efforts towards ticketing those "littering" the streets with these devices, or they may choose to ask the police to create a blitz of enforcement, among the various enforcement options. They may choose to revoke the business license for entities providing such conveyances, or they may choose to enact new taxes to pay for the management.

There are many options, and city governments are entirely appropriate to make the choices. I encourage you to take your grievance there.