Full disk encryption and end-to-end are not really ensuring no one can get it. I feel like I beat this point into the ground in these discussions, but all encryption is weak against rubber hose cryptography. If someone can compel you to give up your device and key, then all end-to-end does for you is make it less likely you will be caught by someone monitoring traffic.

Which brings us to point two: if that's your primary concern, then using Google may not be your best bet. If you are using Google messaging apps, it's likely because you value the additional convenience Google provides and privacy is a secondary concern.