Always amuses me a bit when people say Kindles don't support EPUB, since I've been stripping DRM from my books and storing them in Calibre (enabling transparent conversion between EPUB and Amazon's formats) for thirteen years without a hitch. You should be doing this on any platform if you want to keep your books.
It's beyond me why anyone who so much as knows what FOSS stands for wouldn't do the same.
I've taken to mending the gnat holes on my tshirts with colourful cross stitch over patches and I feel my life is better for it