Telcos infrastructure is so broken. Why does an outage in Tennessee somehow affect areas in California and Texas (depicted in that outage map by the yellow area

Telcos infrastructure is so broken. Why does an outage in Tennessee somehow affect areas in California and Texas (depicted in that outage map by the yellow areas)? ATT and other big telcos need to be broken up, and municipal run ISPs need to become the norm. These outages should be local to the city and not ripple across the nation.