Agreed. This is one of the reasons why we created BookFusion. It allows you to easily organize and manage your eBook collection while being able to read all your eBooks regardless of format on Android, iOS and Desktop(via Web)

BookFusion also has a Calibre plugin that will allow you to easily sync your entire eBook collection to the cloud.

More information at https://www.bookfusion.com/reading/cloud-library

PS: Founder of BookFusion. Will appreciate any feedback that you might have.

Calibre is the library, reading in the library can be less optimal than reading at home :-)