Add some batteries to the meshtatic nodes. and even if all electricity and networks go down, you and your friends can still organize and plan.

Internet outages happen all the time. Most of these networks can run independent for a time. And are designed to be so. Only smaller networks have issues because they are not designed as such. But things like toast make a small store feasible to run. If electricity goes out then it has bigger issues, but I've seen stores go to hand swipe cards before to keep from closing. 

I can only speak for the US, but our electric grids and production are supposed to be air gapped for critical infrastructure. Healthcare? I doubt it based on the continuous leaks there - and medical supply chains are tightly integrated with internet/cloud... Shopping still has a fairly sizeable local accessibility for staple items, certainly food distro where the internet wouldn't matter for at least a short while, but it's also tightly integrated for Supply Chain Management, much like Health care - so there could be a run on it.

I'm not sure on public transport, but most are goverment led, so probably air gapped.

There's also a shitton of dark fiber laying about. Internet infrastructure COULD be brought back up depending on the damage that triggered outages in the first place.

I wonder if that fancy bed company that saw it's beds freeze 'cos no AWS ever sold to hospitals...