On February 26th, Kindle customers will lose the ability to download eBook purchases directly to their PC. If you want to switch to a rival eReader brand in the future, I suggest that you use the soon-to-be discontinued “Download and Transfer via USB” feature to archive your Kindle library.
The files now use a different kind of DRM that hasn’t been defeated yet.
The purpose of using the soon to be removed feature was to get files with an older encryption that can be easily removed