Full Backup of non-rooted device in 2017
Nothing really crucial changed since then. Android SDK is now installed together with Android Studio, however can be installed separately. Platform tools, which contain ADB, are now delivered separately from SDK. Here is the link:

https://developer.android.com/studio/releases/platform-tools.html

After the installation you will find adb binary in platform-tools directory. All other points from those answer are still true.

Consider also TWRP backup possibility, which though, requires TWRP.