phones still work even if the power grid is disabled With the sunset of POTS and twisted-pair copper wire, this is absolutely not the case. At the very least,

phones still work even if the power grid is disabled With the sunset of POTS and twisted-pair copper wire, this is absolutely not the case. At the very least, service continuation now requires 1) cellular masts with reserve power and 2) a charged cellphone (most of which have at best ~24h battery life), or 3) a directly-wired or fibre-based Internet access and 4) battery-backed VOIP or SIP system. A POTS service had its own power supply, independent of mains, with battery back-up, and frequently ran for days even during widespread grid outages.