And I’m pretty happy that students use nowadays google docs. Sure, it’s propiertary and can break at any point, but man if it does not make collaboration easier.
At any time, you can download your google docs data and have it locally. You can convert it to word/excel formats.
This makes anything you are trying to argue completely irrelevant.
If they basically forced you to keep your data in their proprietary format online-only, then maybe you have an argument.. but since this is not true you are grasping at straws here.