> No body has been deprived of anything, it's just copyright violation.
The second part of your sentence doesn't follow from the first. If someone is violating a copyright, that someone else has been deprived of their rights to control their IP, and they're owed compensation. That's the system we set up, so that's the system we should follow.
If a rights holder wants to grant you the privilege of copying the data, that's great. Many of them actually do that. But that doesn't mean we're allowed to just violate the rights of those who choose otherwise. The response should be to consume media that is offered in favorable terms, not to pirate media just because you feel it's convenient.
Granted fair use is a thing, and rights aren’t unlimited. I’m not arguing against fair use, but many here advocating piracy are not arguing from a fair use perspective. Or are you trying to argue that all piracy is fair use? That would be a more interesting argument than pointing at the existence of fair use, not that I would agree with it.
If it's just a backup I can't see any ethical reason why you shouldn't be able to do this.
We went through all this in the courts when we got the rights to timeshift recorded TV programmes.
Comparing it to stealing food is ridiculous. No body has been deprived of anything, it's just copyright violation.