What is the benefit of creating another Workspace?

You get your own Workspace when you buy a  subscription. You invite people to your Workspace, create and work on projects with your team there.

Once you subscribe, you get some storage space, and a certain number of users gain access to your Workspace.

If you have separate projects for a different team then having additional workspaces may come in handy. You have to purchase a separate subscription for another Workspace.

You can separate personal projects and work projects by putting them in different workspaces.

Usually, it's used for teams that don't have common projects.

FYI. You can't Copy & Paste between different Workspaces.