You wouldn’t put on flip-flops to climb a mountain or go running with size-12 sneakers on your size-10 feet. Ocean containers are a bit like shoes: you need the right kind, and the right size, for your specific purpose.
There’s no getting around it: cargo that doesn’t fit in a container costs more to ship than cargo that does. Transporting out of gauge cargo globally is also a more complicated process than shipping a steel box.
But if you do things right, you can control the cost of shipping oversized cargo, and also avoid some significant headaches.