@TotalSonic @molly0xfff In most places, the closest thing we have to this in practice is amateur radio voice repeater networks (which is not a terrible place to start, honestly). SOME major cities have volunteer 802.11 mesh networks running: e.g. https://www.nycmesh.net/

This is not a problem which can be fixed with a website, app, or gadget. (not suggesting this is what you meant) It is a matter of community organizing, knocking on doors, and *off-line* collective action.