TBF:
My two similarly aged non-Amazon EPUB-readers lost the capability to download DRM-books already 5 or 6 years ago.
Certificates ran out, Adobe versions too old, no chance for firmware updates.

Thankfully I am not really affected by it, as l anticipated exactly that early on.
If a book was not available without hard DRM, I would not buy it.
And acquiring it DRM-free by different means instead doesn’t even feel like piracy. More like what I did during open-air-concerts at my old place: bringing a picnic basket to the hill beside the stadion where they took place and listen from there.