Does USB Internet option require root access?
ReverseTethering does not require a rooted device. Depending on your device, it might come with a preinstalled reverse tethering option. Unfortunately, this preinstalled solution is only included in very few devices.

I am the developer of ReverseTethering NoRoot, an app that brings reverse tethering to any Android device running Android 4.0 or newer. No root required. All major host OSs are supported. The app is available on Google Play.