Same is true with an e-book if the device fails the book is gone and with it the information
What you on about ???? ..... It is never gone ............. it is all kept online eg at Amazon.com. If you log into your account from any computer it can be retrieved !

Ps - and as for any other information - there is a thing called dropbox which you should put all documents into to recover from any computer. If you dont save your important information in a cloud you will lose it sometime, be it from your tablet or computer. And lastly Android is all apps - so if you lose your device - just download another app on your new tablet.