> Send the picture to someone at the other end of the lecture theatre? It's likely that there would be a phone network or Wi-Fi available.
Now you're back to using a centralised system using a network you know nothing about, operated by someone you don't know.
> direct Wi-Fi or Bluetooth connection or an AirDrop
AirDrop is not cross platform AFAIK. Direct wifi or bluetooth aren't the easiest to work with for non-technical users.
> A crisis or emergency situation where networks are down? There isn't much population density or movement to propagate the data.
Why not? Do emergencies only occur when people are few and far between? I think I'm misunderstanding what you're saying.
> That's why I personally think that the use case should be related to travel, transport, sport or vehicle-to-vehicle communication. Situations involving movement and loss of connectivity.
That's certainly a valuable use case, but probably not something that bitchat would be useful for.