A couple of thoughts...
Back in 1982, I realised that Apple had not provided their new ][e with back-compatibility. It would not be able to read my ][+ word-processor disks. Swearing mightily, I got a budget serial card, hand-wired RS-232 link to a BBC_B, patched its hand-shake code, exported my documents as plain-text ASCII.
Since then, I've done my best to keep 'base' versions of my documents in TXT or, at a push, RTF format. Yes, I write in Notepad.
Unfortunately, I've had to use PDF for news article / journal down-loads. Finding yet-again that an article references a subscription-only or pay-walled document is beyond exasperating. Sometimes, an Arxiv may be found. Sometimes, 'open access'. Else sigh, move on...
Books: My beloved wife joked that I'd more books than the local library, perhaps enough to re-boot civilisation twice-over.
This despite donating crate after crate of 'thrillers'.
My eyes are not as good as they were, my reading speed has halved, but I can still 'blow through' a fair-sized, well-written novel in an hour or two. I take in the page via a couple of saccades, 'watch the movie' rather than read the words. I literally do not 'see' the words.,..
( Down-side , writing is slow, slow, slow... )
About once a year, I'll look at e-books, but they do not yet seem to have enough page on screen to satisfy me. Besides, bit late to be starting now...
..