Only if your backup (or restore) process circumvents the DRM. But, yes, fuck the DMCA.
On that subject, copyright is a broken system, and I don’t think anyone should feel compelled to participate in it anymore. You should try to compensate creators, but copyright theft is just the norm for corporations now (not just LLMs either, legal fictions have let Disney justify not paying on some of their licenses) so you do you.