How many open source projects have you dug into to verify the internal cryptography does what the project says? Do you always build from source code and install your own compiled binaries on your devices, or do you download and install precompiled software like everyone else? 

 Around 90%+ I'd say. I do compile some of them on my own pc thanks to arch AUR and i'm using fdroid where you can check the build logs thus the binary sources.

Also whatsapp is e2ee, feel free to use it. 

 Absolute cope, holy shit