For me it is not really a problem of books, I did not read many books through Amazon, I usually buy them from authors, or just use the reader to read articles and PDFs. So the real problem yesterday was I wanted to finish reading an essay written by a friend and the book reader did not work.
So what is more justified is switching to a more open reading and listening infrastructure than Kindle and Audible (I use Audible a lot and there I lost access to books I paid for - not even with gift cards).
The real question for me is what is the best non corporate or self sovereign reading experience. Hardware will be probably Daylight, which I ordered and it will take some time to get it, until then I have my Pixel Fold with GrapheneOS.
But what about good user friendly reader app? When I see an article I want to read on my desktop, I clicked one button and then I could read it in the bed.