This is not an anti-Kindle rant. I have purchased (rented?) several Kindle titles myself.
However, YSK that you are only licensing access to the book from Amazon, you don’t own it like a physical book.
There have been cases where Amazon deletes a title from all devices. (Ironically, one version of “1984” was one such title).
https://www.nytimes.com/2009/07/18/technology/companies/18amazon.html
There have also been cases where a customer violated Amazon’s terms of service and lost access to all of their Kindle e-books. Amazon has all the power in this relationship. They can and do change the rules on us lowly peasants from time to time.
Here are the terms of use:
https://www.amazon.com/gp/help/customer/display.html?nodeId=201014950
Note, there are indeed ways to download your books and import them into something like Calibre (and remove the DRM from the books). If you do some web searches (and/or search YouTube) you can probably figure it out.
This should be like a PSA when signing up for internet service. Like, hello new internet user! Welcome to the glorious, uncensored world wide forum of information, of which there is a 30+ year established culture of lying and manipulation in order to get you to buy things and/or steal your information in order to advertise to you. By the by, should you sign up for one of the hundreds of content streaming services, YSK that none of the content is yours to own ever. If it’s not physically in your hands, it’s not yours.
Even if you can physically hold it, you better be damn sure it will work without internet.