Have we learned nothing? This is literally what happened a few years ago with the big Optus outage. They were doing a change overnight, and broke everything. But all the on-call technicians were asleep because nobody could call their Optus phones to wake them up. Couldn't even try to raise them with email pings because their home Internet was also Optus. Management were clueless, because nobody could call them either.
Everyone found out in the morning from the news or when they rocked up to work per usual and the place was an ants' nest.
Issue some people phones on a different carrier, for pity's sake.

This one's a little more nuanced. The government owned (and sold off) the old copper phone lines. And yes, that sale hurt the people for two decades.
The government did not have 5G data towers. Hell, they didn't have 3G data towers. There were some 2G towers, but most of the mobile network at the time of the Telecom sale was analogue.
They have had government assistance/incentives while deploying mobile towers in rural areas, but they have pretty-much always privately owned their mobile telephony infrastructure.