I wondered what you do with the slides, negatives once scanned? Do you keep them? I’m aware of silver halide photos have been used as an archiving method (lasts 100 years or more). I assume?? the slide/negative plastic might last longer than a digitised copy file on computer storage media (and media that can be read – e.g. because of the way computers change, the files would have to be transferred to newer and newer storage media, to keep a usable copy). The original slides could be scanned again and again (unless they become so brittle, that they fall apart). I don’t think I could throw out my slides and negatives (IF they were scanned), though probably wouldn’t ever use them again. Hard to let go but it would create a bit more space.