alt Hacker News"The internet no longer exists" is a particularly extreme subset of off-grid scenarios. For the more plausible off-grid scenarios—the ones that have actually happened—the unavailability of the internet has been varying degrees of localized and temporary. In that context, being able to bootstrap the entire network without any reliance on internet infrastructure is more of a convenience than a hard requirement.
In particular, it seems obvious to me that any preparedness plan that requires a user to acquire in advance specialized hardware (eg. a battery/solar-powered long-range radio of some kind) to be used with an off-grid network can reasonably expect that user to also be prepared with the software to drive that hardware.
The whole project is a convenience. If I were in a situation where I actually had to rely on Meshtastic for comms, I'd be pretty nervous. It doesn't really work that well. Luckily, I've only enjoyed Meshtastic recreationally. Where this comes from is from me trying to learn about and set up some nodes on vacation in an area with very limited internet. I followed the tutorials, thought I had what I needed, but I was wrong. Woops, documentation is online. Within the community, I've seen "that same thing happened to me" more than once.
As with many hobbies, this is a "just because I can, I will" type of thing.