> With network protocols, you make one layer (Ethernet), you add another layer (IP), then another (TCP), then another (HTTP). Each one fits inside the last, but is independent, and you can deal with them separately or together.

It looks neat when you illustrate it with stacked boxes or concentric circles, but real-world problems quickly show the ugly seams. For example, how do you handle encryption? There are arguments (and solutions!) for every layer, each with its own tradeoffs. But it can't be neatly slotted into the layered structure once and for all. Then you have things like session persistence, network mobility, you name it.

Data formats have other sets of tradeoffs pulling them in different directions, but I don't think that layered design would come near to solving any of them.