Big DS and I found a compromise on the lunchbox/bag thing. I pack a brown bag with the sandwich, snacks etc. and put it INSIDE a "lunch bag shaped" insulated bag, on top of an icy pack and his drink. This way he can just grab the drink and the brown bag.
DS has a turkey sandwich, drink, applesauce, 2 kinds of granola bars and a PB crackers. I'm out of pretzels and he's not happy
The younger 2 kids are buying chicken nugget/tater tot lunch at school. They still have to bring fruit, snacks, etc. since all you get are the chicken nuggets and tater tots.