Not sure why you think this.

You just reiterated what I said.

If you were to rip a Bluray to your computer, you’re legally not permitted to watch that movie if you’re no longer in possession of the disc.

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You can legally rip a Bluray for backup purposes. If you sell or give away the Bluray, you have to delete the backed up copy.

Technically, if the FBI were to ask you to prove ownership of a digital copy and you had lost the disc, it would be illegal to retain that digital copy.

Bypassing DRM is illegal because the DMCA explicitly prohibits the circumvention…

Yes. The Digital Millennium Copyright Act is a law that covers copyright protections.