Leaking lift gas is expensive & difficult to prevent. Also explodey! (if H2).

Airships have to have enormous volumes to float. Therefore they have a lot of drag compared to their payload capacity (Vs. heavier-than-air-craft). So they aren't very good at dealing with wind in an efficient manner.

Expensive OR very cheap and explodey. (Gasoline is also explodey)

~$2 per 10kgs of lift if my internet calculations are correct.

But I guess if helium isn't lost at a great rate, it might be a cheap part of the whole setup.

I'd say the major problem is that the niche may be too small to amortize construction cost across a big enough fleet. A reduction in global poverty may be able to increase demand to make the niche market big enough to be viable. For now we wait.

https://en.wikipedia.org/wiki/Grand_Fleet

Lighter than air is pretty decent at going up, but not much good at the lateral motion bit.

An airplane only stays aloft as long as it is being propelled, after that, it's basically falling with style. Likewise, a lighter than air craft is just floating in the wind without being propelled, so the key is which is easier to propel, thus, it compares well to just throwing an object.