It isn’t just deployed by nerds but sometimes also by cafes, libraries and municipalities. So you can expect them to be in every town but they don’t have such a dense coverage that they have a full mesh network over a city.

And the thing that is missing is that there are no inter network services like an copy of Wikipedia, LLMs or fileshares.

https://freifunk.net/

They have their own antennas. If the internet connection of one router dies, but it has a connection to another Freifunk node, it gets routed over the other one.

There is freifunk in Germany they use Mesh Network -> Router > VPN to another Country so they dont get Problems by People pirating.