HDDs are a pragmatic choice for “backup” or offline storage. You’ll still need to power them up, just for testing, and also so the “grease” liquefies and they don’t stick.

Up through 2019 or so, I was relying on BD-XL discs, sized at 100GB each. The drives that created them could also write out M-DISC archival media, which was fearsomely expensive as a home user, but could make sense to a small business.

100GB, spread over one or more discs, was plenty of capacity to save the critical data, if I were judiciously excluding disposable stuff, such as ripped CD audio.