But then what's the "Eclipse Workspace" good for? What does it even mean to have an "Eclipse Workspace" ?
This is for project metadata, and shouldn't be confused with the actual data of your project.
- Those data can be stored in a git repo anywhere on your disk.
- the Eclipse project can be imported in an Eclipse workspace, for Eclipse to work with.
That is why, when you delete a project in Eclipse, you can simply "unreferenced" it form your Eclipse workspace, while keeping it on your hard drive.