Why are airships not more popular?
Airships are much more susceptible to bad weather. With an airplane you can pretty much count on it taking off on time and arriving within a couple of minutes of the scheduled time. This allows operators to employ their aircraft with a reliability which an airship will never be capable of. This means that the investment made into an airliner will lead to a predictable stream of revenue and (hopefully) profit, whereas the airship might need to wait several days until it can take off again, or headwind  might delay it by more than a day on a long trip. In this time, it will accumulate interest and fixed cost, but no additional revenue.

Scheduled air services were indeed first done with airships, but as soon as dependable aircraft were available, only a few niches like transatlantic travel were operated with airships. As soon as airplane performance covered those niches, airships became obsolete.

Today the most credible use of airships would be transportation of heavy equipment into remote areas. Tourism could be a second use, but the number of airships needed to cover this market is small. Airships do have some benefits:


no need to build roads or runways
carrying of outsize cargo is no problem
if the airship is big enough, payload can be immense
destinations can be anywhere, not only on a coast or a big river (where regular ships cover this niche more than adequately)


The few cases where the airship could be employed gainfully would not cover the expense of developing and building one. Development cost alone would be similar to the development cost of a new airliner!

But if we look back in history, even at a time when airships were available, big transportation tasks were done by aircraft. Papua has impenetrable jungles, and to transport dredging equipment and personnel to the Morobe goldfield from 1932 on, aircraft were used rather than airships. The huge dredges were dismantled for air transport and flown into Bulolo, where they were re-assembled and put to work. With a Zeppelin, less dismantling would have been needed, but just the complication of keeping the airship balanced when the load is released made this option less attractive.

For the history buffs: To transport very long items like the dredge shafts, a single-engined Junkers Ju-52 (Ju-52/1m) was used. It had a detachable rear fuselage with  automatic couplings for the control rods. Spherical collar screws ensured precise positioning of the two fuselage sections.