Actually I always wondered what would happend in an All Charedi society on Shabbos
We are backwards people and we want to live in the stone ages.
No! We would follow halacha.
You Need people to monitor the Electrical Board for the Electric Company (There ARE people who need Electricity to Live like people on ventalators and Hospitals)
We would follow halacha. Probably we would have neighborhood generators like in Israel.
You Need people to man the 911 call center (or whatever you have instead)
Hatzala operates on shabbos in every community. It works fine, and is perfectly muttar.
You need some pharmacies to be open for emergency drug supplies
I’m sure we could figure something out.