Some have speculated it's complying in advance with stealth editing of books to remove whatever content has been decided to be censored. If you can't download the original copy and keep it, they can change the one you have and make it seem like the original text never existed.

The kobo unes run Linux ootb, and they are as easy to install something like pluto on as an android one, but I still prefer them because I can do all kinds of shinanigans with the command line

Also if they are too expensive for you, just get a used one, as long as they have a backlight you can read just as well on them as a libra color

It's because the first few generations of DRM were extremely poorly implemented. My og kindle keyboard still works and will ignore the DRM (that would be locking me out of, for example, a library book after its due date) if you just change the file extension to one of the DRM free file types. It will also then let me distribute that ebook to others without restriction.