one isn’t supposed to move the camera
Depends on the effect you want. You can do lots of cool/cheesy tricks by moving the camera, like putting the sky from a different place into a different photo, or seeing stars inside a person silhouette. That’s all double exposure, regardless if you like or consider it “proper technique”.
I don’t think Lemmy is more privacy friendly. In fact, its, arguably, even less privacy friendly that others.