Environment
- Republic Wireless 3.0 phones
- Android 10 and higher
Answer
The Facebook App reinstalls itself due to it being a preinstalled App on your phone. If the App didn't come with the phone, it would have been added in with the Android 10 and higher software updates.
Additional Notes
Like many preinstalled/"shell" apps, it may not be possible to fully uninstall this app on some phones, depending on the model. However, you can completely disable it if you do not want to use it.