Some loads simply don't fit on trucks, or rather on the roads that the trucks have to use. Heavy lift airship would operate in a market segment that does not even exist without them.
Big transformers are now limited to boat transportation, and it's a constraint on grid design. I assume this is also the case for other industries that become river bound but wouldn't necessarily be so if not for equipment transportation. So this could be a game changer (more so I think than this faster than boat slower than plane thing).
Wind turbine blades is the obvious one. On-shore turbines would be much larger (which btw implies lower rpm, which implies being less annoying) if they were not constrained by land transport.
