Since last year Amazon doesn’t let you download your books as files from the web anymore. You have to sync purchases to a (presumably supported) Kindle device. I have a jailbroken Kindle and was shocked at the added hoops to read a legally purchased book.

Obviously the solution is to stop supporting Amazon. Some authors unfortunately only sell ebooks there.

Yep. I moved off Kindle onto kobo several years ago. I would still buy books on Amazon if they were only available there, and used dedrm to move them to the kobo. That doesn't seem possible anymore, so I guess I just won't buy anything from Amazon now.