For the small minority who like reading books on e-ink readers and don't want to use Kindle, options are shrinking.
"Why buy ebooks?" a smug millennial asks. To support the authors, of course. A pittance from a publisher is more than they'll get from a torrent.
Kobo, the Canadian e-book company, has been the Kindle-alternative-of-choice for the past couple of years. They manufacture the e-reader hardware and also offer a selection of books in epub format. (Adobe DRM'd, but that can be, um, dealt with; also DRM-free, which they sell but stopped flagging in search a few years ago.)
Apparently Kobo has been struggling, though. First they merged with a Japanese company, Rakuten, and now Rakuten Kobo is "partnering" with Walmart, the Bezos of the Arkansas hills. Simply pathetic.