Amazon just changed how e-books are downloaded on its older Kindles, and not in a good way

It's no secret that, compared to other e-readers like those from Kobo or Boox, Amazon's Kindle devices are far more locked down. That makes it difficult to customize your Kindle or manage the books you've bought the way you'd like withoutjailbreaking it.

Source : https://www.pocket-lint.com/amazon-changes-drm-system-on-older-kindles/