What if airships instead of being rendered obsolete as passenger carriers by planes they instead end up being used for cruises, a capacity in which planes could never be used? You account for the large operating expenses of airships by selling tickets to the wealthy. Airship cruises could probably lead to the passenger use of airships for much longer into the 20th century and perhaps even to the current day.
The challenge is to avoid the stigma of airships as unsafe, and build confidence in them as a means of transport. Popularizing air cruises is I think the easier part, since really nothing can compete in providing the same sort of experience, plane trips are too short, and I'm sure wealthy people will find luxury airship cruises to be an attractive experience they'll be willing to pay for.
How can we maximize the passenger capacity of airships, the flight time without refueling, and other things to optimize cruise airships? How can we have several cruise companies competing in the airship cruise business leading to greater research and development in improving airships for cruise purposes and suchlike? What do you think an airship cruise would look like in more modern times?
How can the technology develop, for example airships augmented with jet propulsion?