There was an HN post a few months ago in which vulnerabilities and history were discussed at length: https://news.ycombinator.com/item?id=28119943
Explosiveness of hydrogen is only one of numerous issues. Airships are large, vulnerable, delicate, and complex systems. Neutral-bouayancy craft such as airshpis and submarines (as opposed to positive bouyancy craft such as surface ships, or lift-based craft such as aeroplanes) are at unstable equilibrium, in which a deviation from stability tends toward a positive-feedback loop. Subarines at depth "want" to sink lower, airships at altitude to fly higher, until crush or rupture levels are reached.
Airships have exceedingly poor high-wind handling capabilities.
The final question is whether or not they're even ideally suited to the roles envisioned.
For global cargo, with relatively short tunnel crossings, it would be possible to provide a linked rail network from Tierra Del Fuego to Australia and South Africa, via the Bering Strait and Java Sea.
The submarine "floating tunnel" concept proposed for Norway's fjords might make for a viable transatlantic rail link. This is a proposal which has actually been made, and which would allow for crossings in from 2 days (at 100 kph) to a fairly attainable 10--15 hour crossing (320--480 kph), and possibly faster (using hyperloop-like designs). The slower rates would be quite sufficient for most freight.
And airships would hardly be any faster (top speeds are about 160--240 kph), with vastly lower capacities.
Aerostats seem like useful tools for reaching and remaining at high altitudes with low energy expenditure, but not much else.