Books enter the public domain. Project Gutenberg and others produce DRM-free versions. Many academics and people who wish to share their knowledge also publish works DRM-free, sometimes under permissive (copyleft), licenses.
The fact you see DRM as the norm and non-DRM as “a unicorn” that “doesn’t exist”, is mildly sad. You should explore all of the above a lot more, and much more besides.
Mildly sad is also that you seem to fault GP for not “exploring” more, instead of the insane practice of DRMing everything in the first place. I never have purchased DRM protected media and never will - I’d rather pirate everything digital and but physical hard copies.
> Books enter the public domain.
...and then they get re-packaged with DRM on Amazon's store, mostly because people uploading public domain books on Amazon have no idea what they're doing.
> Project Gutenberg and others produce DRM-free versions. Many academics and people who wish to share their knowledge also publish works DRM-free, sometimes under permissive (copyleft), licenses.
You can read DRM-free stuff on a Kindle already, so that's not particularly relevant here.
> The fact you see DRM as the norm and non-DRM as “a unicorn” that “doesn’t exist”, is mildly sad.
When every big publisher is doing it, it is the norm. That doesn't mean there doesn't exist any book publisher which doesn't do this, but the vast, vast majority of the books actually sold today contain DRM. We don't have to like that norm, but pretending it isn't one is just denying reality.
I assumed that that was clear from the context, but let me rephrase it then:
"being made available DRM-free on Amazon" (and I'd narrow that down to "primarily/only on Amazon")
Of course public domain books are DRM free but I'm getting those from Gutenberg, not Amazon. Likewise, the copyleft books I'll most likely download from their own homepages, not Amazon.
I'm aware that DRM free media exists, including for currently copyrighted content that Amazon distributes ;)