So the airship puts down a container. Now it needs ballast for not launching in the stratosphere with the reduced weight. You could use water because it can be

So the airship puts down a container. Now it needs ballast for not launching in the stratosphere with the reduced weight. You could use water because it can be easily pumped into the airship, but water is not everywhere. Now you need a truck to drive enough water to the destination … I'm not saying it's impossible but its a big hindrance. Fun Fact: In the late 90s a german startup named Cargolifter tried this idea. They build a small prototype and one the biggest airship hangar in the world. Then they ran out of money. The hangar today is a tropical indoor water park.