There are other uses for virtual backgrounds in Zoom besides my bullet point idea. If you're teaching from home, you might just want to hide or improve the background. If you've positioned your webcam/ laptop in your classroom in such a way that the background includes other students, you might want to use virtual background to hide them. Or you might simply want to use a virtual background as a means to inspire curiosity. If I was still teaching social studies instead of computer science, I'd be tempted to use pictures of UNESCO World Heritage sites in my Zoom virtual backgrounds.
If you've never tried using a Zoom virtual background, watch this short video in which I explain how to use a virtual background and share some good places to find virtual background images.