The thesis with the airships is that the given history of flight doesn't really make a lot of sense at all. You would think that aerial travel would be heavily funded and researched if such a concept were to be discovered but according to what is noted in mainstream history there was an unreasonably large gap in the timeline from when the tech was invented and when it was made slightly larger so a person could stand in it.

According to given history, the first time a man left the earth in a device suspended in the air was in the 1700's but according to the same given history this tech was actually invented in the mid-200's in China, used as military signals, which means that we are supposed to believe that a near-zero amount of interest, funding, and research was put into this endeavor for over 1,000 years.

But of course there were many flying machines long before the Montgolfier brothers. They are just classified as myths. And the funny thing is that we can 100% confirm they existed almost 3,000 years ago.