"If a big earthquake temporarily disables a chunk of communications infrastructure." OP is talking about the kind of thing that kicks in if that cell phone network, or 911 response, or what have you is compromised.

I do believe there have been instances where ham radio operators were able to deploy recently and get comms up in some areas faster than others would. These were disasters where they took down the towers, because it happens. And the local hams are faster than the cell phone company is to deploy something.

Ham range can be 100s or >1000 of miles. Cell towers much shorter, under abs max ideal conditions 45 miles. And require much more config and admin.

Hams aren't "motley." They're well-organized. That's why they appear to you as "preppers."

The ARES people think they're really relevant at least here in Europe. I don't join them because they take it all too seriously IMO. They have this thing where a minor flood happens and they all come out in tacticool gear and pretend to be important but keep running in the way of the real aid workers. That was at least my experience when there was a "deployment". Perhaps in other countries it's different.

I don't care about being "important". I'm more into the hobby for the technical side.