Certain ‘mobile’ devices (e.g. iPads) can also sometimes have physical keyboards attached. There should be an option to hide the mobile toolbar if an external keyboard is attached, but for it to reappear once the keyboard is disconnected (so the user is using the on-screen keyboard).
The mobile toolbar is a waste of screen-space for anyone using an external keyboard who is familiar with the necessary keyboard shortcuts. Disabling such toolbars when keyboards are attached is pretty standard in mobile apps.