I've heard the reason why the chip bags are full of air is to cushion the chips so they don't get crunched as easily when packaging them. Also, the air isn't just oxygen. It's supposed to be a gas (forgot the name of it) that preserves the food inside so that they don't spoil before the bags are opened.
I'd rather get lays, sure i can tip the pringles can to get the chips but that's not what god intended so i don't participate. I actually just like lays flavor better.