This implies that governments didn’t already have this ability, which appears to be largely untrue? To my understanding, many countries already had emergency messaging systems, and mobile integrations are just a way of modernizing them.
(It seems exceedingly good that the government can warn every civilian about natural disasters, etc.)
Governments had poorly thought out poorly secured barely functional systems involving the network operators and those were then integrated with default system apps that have terrible UX without fixing any of the problems AFAICT. Agreed that it's clearly necessary functionality but it's worse than useless when it's so far proven to be (at absolute best) a constant stream of irrelevant alarms.