I was reacting to (should have added a citation) : > I think there is actual technical reason why Amazon don't adapt EPUB natively

Kindle is out since 2007, KFX was released in 2015, hopefully when you create your own format there is some advantages.

In the end it appears we agree that the position of Amazon is : "Why invest time in something that is only for people who aren't using your platform?" But we probably disagree on the answer to it :D.