> but without enough structure (or mass appeal) to take off

I think the most important requirement for a mesh technology to take off is a purpose that is practically relevant right now. Let's assume the mesh network exists - now what? Now you can send messages to other nerds but ... what do you even want to send as a message? That's why ham radio basically bottomed out at contests, Morse code challenges and exchanging specs ... there is nothing to say. Maybe the biggest problem of mesh networks isn't technology but society. If there is a purpose that at least serves nerds making up 0.1% of the population then that would be amazing and mass appeal would actually be more cause for trouble than desirable.

I had a friend who worked in telco as well, and he told me the reason why IP-based networking solutions will never completely replace earlier stuff like GSM is that the QoS algorithms used work extremely well in practice (which mesh networks prove), their behavior is completely nondeterministic, and tends to have really bad failure cases in overload, or certain nodes in the network failing.

Which means in SHTF situations (such as one when most people imagine this would be useful), these things tend to fail the most.

LoRA can work but there needs to be a backbone, either terrestrially via towers with repeaters or LEO constellations. Everything else is doomed to fail.

I believe it's called ham radio