Truth is that, as long as the cell phone system works, there doesn't seem to be much need for ham operators to pass "Health & Welfare" messages ("I'm okay, etc.") between affected members of the population & their out-of-the-area relatives. If ths cell system is overloaded, people are often able to send text messages.
I do wonder, however, about the FEMA report for hurrican Harvey that listed 4% of the cell towers down & about 5% for homes affected by serious flooding. My guess would be that these two percentages represent the same geographical areas. If ham operators had been available to take outgoing messages by, maybe, FRS & GMRS radio, marine radio (in some areas, a lot of people have a boat & a marine band radio) or even CB, they might have been able to offer a useful service. Many hams were certainly busy supporting local agency emergency communications. But I'm guessing not all of them.
With hurricane Irma, FEMA didn't list any dead cell towers at all (really?).
Radio Relay International (RRI), a split-off from the ARRL National Traffic System, has a plan in the works to revive something called the National SOS Radio Network, which links up volunteers & the population by the radio services listed above. RRI would provide the "long-distance" part of the deal. Such a thing might have been useful.
That's for the OUTBOUND messages, sent by people affected by the disaster to their relatives & friends outside the area.
With the two mainland US hurricanes, we also got a few requests from people "on the outside" who wanted to send inquiries into the affected area. There were even more requests for such with the "DX" aspect of hurricane Irma, hurricane Maria & also the Mexican earthquake that occurred in the middle of all the wet & windy mess.
"Can hams get a message into Haiti?" "Well, maybe. In normal times, Haiti is pretty rare DX! We can try, just wait a few days."
Generally speaking, INBOUND messages to a disaster area cause more problems than they help. They are almost impossible to deliver to the recipient, if those people are evacuated or displaced. This is especially true when the storm is still going on! (Many people outside don't seem to think of this!) They (the inbound messages) suck up the time & energy of the hams on the ground, who are trying to support local agencies. So we try to discourage even taking such messages on. At the very least, they are likely to be held up for days & the senders need to be informed about this.
However, there were at least two groups that advertized on internet (Facebook, etc.) that they could "queue up" inbound inquiries until such time as conditions improved. I did make use of one of these. Outbound messages were being handled right away. Probably none of this traffic was in the form of radiograms. The "internet" can extend a long way via radio through use of stand-alone mesh networks & Winlink. A radiogram is just text, however. It can ride on an email, but it can also go places other free-form email texts cannot go (on CW, for example).
When "things happen" (TSHTF?), we use the methods available.
Yes, I realize that the Red Cross, Salvation Army & even the hurricane weather nets passed a lot of welfare traffic, for people in their shelters. Can they get out into the communities also? RRI seeks a way to be useful in the organized chaos & they should be learning how that's done, this week. The National SOS Radio Network reboot might do that. Especially if the volunteers & routings were in place ahead of time. Routings are RRI!