Sony explains why the Dualshock 4 lightbar exists.

[archer9234]

The light bar should just have a off switch. It has a dim option now....so.....where's the next step. And its six LED lights. I disabled mine by removing the LED from the circuit itself. I can easily put it back in. But come on. Dumb. It does improve battery life. Around 1 to 2 hours.