If you want to escape the Amazon ecosystem, then alternatives do exist for desktop users.
Alternatives To The Kindle Desktop Reader
You can also share the same collection, keep your saved position and sync it across your devices, and do the same with any book annotations you make across all Kindle products. For instance, many of the accessibility features are common across all Kindle products, although the Kindle devices lack some of the more advanced features like text-to-speech. Otherwise, there really isn’t a huge amount of difference between the Kindle desktop app, Kindle mobile apps, or Kindle devices themselves. mobi eBook files using the Kindle app natively with no additional fuss. This leads to another direct advantage that the Kindle desktop app over other Kindle products.