Docker Desktop includes the easy to run Docker Engine / Docker Machine. I think is fair to assume that most of the revenue is not from users that want a GUI but from users that want a stable Docker Engine experience.
Anecdotal, but my experience, as someone who gives DevOps professional services for many organizations, is that windows users that need containers know that they are called Docker and just download that. Must of them absolutely need GUI. Most of them doesn't know that Docker Desktop requires license, and I convert them to Rancher Desktop.