Early bird trading like the name equates, it's being earlier than the majority. This pattern of trading allows you to make a quick gain when the market is still less volatile, because traders are still warming up to go in full trading burst.

Benefits of early bird trading are much, you don't have to worry about volatility, market is still sleepy and you could cut one some profits multiple times.
You exit trades before the main volatility burst and you can relax or watch for the rest of the day after making profits