The unknown is the lifting gas helium is expensive and hydrogen can leak and go boom. But the speed does not necessarily matter if the cost is much lower and sustainable
Technically you could build an airship that only uses power to get into a jet stream then floats across the Atlantic on the wind saving tons of fuel, but then you've reinvented a sailboat in the sky and the buoyant force of water always beats that of air. So you might as well put your cargo in an actual sailboat and get there faster (see ocean currents v wind above them) without needing to "fuel" the thing with hydrogen or helium.
This is just one example of the cross-section we can't escape. It is as tyrannical as the rocket equation is to space travel. For anything to be a viable transport, it needs to go faster, use less fuel, or carry more cargo than other modes of transport.
Or the 747-8f if you are in a hurry.
https://en.m.wikipedia.org/wiki/Boeing_747-8#747-8_Freighter