I've always told people, Kindles are ereaders seeming designed by people who hate books.

The renderer is atrocious and is holding back the entire industry, much like IE6's crappy renderer and monopoly on users held the entire web back a decade. Browsers (and thus ebooks, which are just HTML/CSS) can now do pretty decent typography, but Amazon inexplicably refuses to get on board with epub.

Their file formats are equally garbage. Mobi, a format that has hardly changed since circa the year 2005, was still in active use until just recently. Their other proprietary formats are confusing in feature set and are opaque to create. The official tool to create Amazon ebooks only runs on Windows![1]

Kindles still can't natively read epubs, but since they accept epubs via email, their customers get confused and email me about it. (Epubs sent via email are quietly convert to Amazon's propriety format, meaning all bets are off on the result. Good luck, publisher!)

I always tell people, buy literally any other ereader.

[1] Calibre can also create them but it's reverse-engineering and not the official implementation.