> ~50 years

That’s very carefully handled books.

My kids books are in no shape in a matter of months. Then adults also spill, grease, and tear their books. I had to buy some cheap second hand copies for a series with no digital release and they’re gross, I made them grossier, and they’re going to the trash bin after me (there’s no shortage of them in the world).

My amazon account is outlasting most physical books I bought in these in the last decade (I also hate amazon kindle’s lack of book organization, biting me hard at the number of books I have, but that’s another topic)

PS: for people going through 3~4 books a week, storing books for 50 years is a nightmare.

...this'll sound rude, but I've never understood how people do that to their books.

I have original-run Animorphs books, over 20 years old, from when I was age 8-13, all looking near-new. The pages are a bit yellow from age, but there's otherwise no damage. Same for the rest of my collection (some of which were published earlier, though I think Animorphs might be the oldest-printed ones I have).

which is why you should get your e-books as drm-free local files

And store those files where? Do you own any working digital media from 1969? I know my carefully curated collection of 5.25" floppy discs are all corrupt and unreadable today.

This is entirely off-topic re: ebooks, but I, too, have lost data that I'll miss. All of my data on 3.25" drives is likely lost, not to mention most of them have been thrown away. I do oww a USB floppy disk drive that was a gift from a friend that visited Japan (it brings me joy). More shockingly to me is that some early USB drives I own have failed.

The collection my have been careful curated but it was improperly stored. The (onerous) way to "store" them, (in hindsight,) would be to copy each of them would have been to copy them all to 3.25" disk when those came out, then (briefly) to zip disks, then CD-R, DVD-R, Bluray-R, and then also included a drive to read them in this backup, once it became apparent that spinny plastic frisbees were no longer a popular data storage format. Or copied the data to archival LTO tape, going up in number as new standards came out.

Or instead of moving between archival format, the other options is to copy it to hard drive and keep moving to bigger and bigger drives, and have online copies and not offline.

If that all sounds too ridiculous and no sane individual would ever do that: you're right and we hang out on /r/DataHoarders.

I’d argue we have countless of digitized books, photographs and movies from way before 1969 that we wouldn’t get access to in physical form.

They might not be our individual personal copies, but they’re there, actually accessible.

To your point, I am strongly for enforcing DRM clearing after the copyright expires or the entity owning them goes under (it should be required by law IMO). I also think collectively we have a fighting chance to preserve copies as long as they’re free of DRM.

> Do you own any working digital media from 1969?

I don't know if they're from 1969 - but I do own a few punch cards...

Temperature variation? What was their advertised lifetime?

I don't know. They were only consumer-grade disks. It hardly matters because I don't own any machine with a working 5.25" drive anyway. Some of my old files I did copy onto CD-Rs in the early 2000s -- I wonder if those are still readable?

The point is that it's actually fairly hard to beat acid-free paper for archival storage.

Well offline storage of digital information is much more complicated than keeping a book around. I had countless external harddrives cds and floppy disks fail on me.