And I'm talking about video calls during work. Exactly what do you think I'm speaking to? Your comments are about work. If you're referring to the joking part, I wouldn't think you would be so naive not to consider people will work from every location in their home or get on calls in public.
There are people who live in one bedroom apartments or studio apartments with no where to work. You could live in a house and the same could be true. the average company doesn't want to reimburse you for work stations at home and alot really want you to bring you ass into the office building(s) they are leasing. The purpose of the backgrounds is to provide a certain level of privacy, so no one knows anything about your home including you possibly working in your bed. The question should be why everyone doesn't take the time to get a background, groom and fully dress.