Water weighs about 8lbs/gallon (1kg/L). When you’re eating soup, the actual flavors/salts/veggies take up about 20% of the weight, tops. Additionally, volume is far decreased, so you can have more food in a smaller container. Finally, bacteria have nothing to work with in material without water. Just add your local water when you need it, it’s already there.
So, buy dry goods to reduce shipping costs for both you and the producer. Ship only the food part of food, not the water. The costs are much lower, for all the reasons above.