You don't need a radio license to receive radio messages, that is valid also for satellite messages received on walkie-talkies.
This fact alone is incredibly important to at the very minimum known what the heck is going on. Suddenly you have a cheap device in your hands that can receive updates relevant to survivors and victims.
In Portugal exist the 3-3-3 plans for anyone to practice using a radio. These are regular-weekly sessions with a lot of people joining.
That is a question you can answer yourself when trying it out.
In Portugal +90% of tetra stopped working. DMR only locally.
Satellite APRS continued working. Who will listen? Well, those from north to south on the country were listening. More important, they were listening who was still active because those were the stations running with their own energy because even FM stations started to go down quickly as the generators ran out of fuel.
Had the blackdown lasted a week, those with a 20 euros walkie-talkies would very likely be the only ones still capable of +50 km distance communications and +1700 km reach using satellite APRS text messages.
Try to see from it from that perspective. You really won't have electricity nor cellphone coverage and not even FM in such scenario.. It's all gone.
But who will send messages to you? Including satellite messages?
In most countries emergency services have moved over to tetra or dmr, with encryption, and all the public related info is broadcasted on "normal" broadcast fm, where you need a normal fm radio, not a ham transciever.