“Success is stumbling from failure to failure with no loss of enthusiasm.” - Winston Churchill
Hyperloop (and vacuum train systems for the ~100 years they were called that before the Musk rebrand) had physics problems, and no matter how hard anyone tried, they were guaranteed to run into them. Cargo airships also have a physics problem that make them absurdly expensive and risky to put cargo on. In both cases, this is an idea that is 100 years old and where the physics has been studied. This time is not different unless you have solid reasoning.
Contrast that with rockets, to use another Musk example: Rockets are well within the bounds of physics, but a hard engineering problem. Landing a rocket propulsively was also known to be an "impossible" engineering challenge that was first demonstrated in the 1990's (with too low reliability).
If they can't do that, at least they could be competitive.
That is not a winning combination for putting any kind of freight carrying out of business. The main reason people use air freight today is to get something from one continent to another in 24 hours. Airships will never do that.
No it wasn't. It was done many times in the 60s and 70s — e.g. all the moon landings.