Back up your Amazon-purchased e-books now
Use Calibre to Back Up Your Kindle Books Before February 26:
Amazon just announced that you have until February 26, 2025, to download your Kindle content. After that date, you will no longer be able to access the books you've paid for if you have a legacy device or a Kindle that has experienced wireless issues. The only way to load what you've paid for onto a device will be through wireless sync.
Have you, like me, have purchased e-books through Amazon? If so, you had the option to "sideload" these onto your Kindle by going to a specific page and select "Download and transfer via USB".
Nifty — but also necessary — feature if you, also like me, run your Kindle in permanent airplane mode.
This will no longer be a viable option ten days from now. So if you have purchased e-books with Amazon, but haven't downloaded the actual files, you should do so now to make sure you have the files on hand.
Another good thing about this option was that it made it fairly straight forward to remove Amazon's DRM lock from the files. (More about how in the linked article from AppAddict.) Meaning you could read the books you've purchased wherever you preferred, without being tied to Amazon's ecosystem. This may or may not be legal in your jurisdiction, so I'm not necessarily condoning such frivolous behaviour.
I'm sure Amazon removing the feature has nothing do with this.