Well, except that aircraft pressure is applied outside-in while soda can pressure is inside-out. Put some outside-in pressure on a can, and see how well it handles it.
Both are engineered in a way to make pressure not a problem. The can is subject to stress if you refill it, the airplane is a bit overengineered so it's not subject to stress. Increasing the width of any wouldn't lead to an increase on their safety.
Sorry I'm confused by your statement. The air pressure inside an aircraft during flight is much higher than the air pressure outside. So the pressure is also inside -> out, same as a soda can.
Both are engineered in a way to make pressure not a problem. The can is subject to stress if you refill it, the airplane is a bit overengineered so it's not subject to stress. Increasing the width of any wouldn't lead to an increase on their safety.