Except the power button, why volume keys are the last physical keys on phones?

[Jenny]

I had this strange question for a long time...
I mean, why are they volume control, instead any other options? It can be brightness, WiFi/Bluetooth/GPS toggle switch, etc...

[Monkeh]

Because volume is about the only thing you'd want to manipulate regularly without waking the screen or removing the phone from your ear..

[magic]

Because kids these days use them instead of walkmans, tossed in a pocket somewhere.

[Twoflower]

I like to change the volume without looking at the phone or without removing it out of my pocket. And try to change the volume with gloves on if you have a screen volume slider.

And yes, I'm still using a phone with a 3.5mm jack.

[Jenny]

Because volume is about the only thing you'd want to manipulate regularly without waking the screen or removing the phone from your ear..

This one seems reasonable...
Thank you everyone.