Back in the 2.xx days rooting was basically mandatory to get decent performance and regular updates, but now the OS is more optimized and has most of the features of rooted devices anyways. Regardless, Google is trying their best to kill off rooting and custom ROMs. Apps like Snapchat and Google Pay don't work without hacks on rooted/unlocked devices because of Google's SafetyNet, which is a huge disincentive to root