Think a little more broadly. I live in Scotland and in the Scottish Highlands there is good cellular coverage, but there are places with no coverage. It's not just travelling on isolated icy roads without phone coverage that is a risk, but I go hillwalking every opportunity I get. It's easy to fall and injure yourself and indeed sometimes people get caught out in bad weather (I was once caught on a ridge when a 90-mph-wind-hail-rain-snow storm hit earlier than forecast and barely made it out alive). Currently I use an emergency personal locator beacon (like a personal EPIRB), which is basically a panic button attached to a radio that signals an old satellite. The time for that signal to reach the rescue teams could be as long as 3-4 hours, and you can add hours on top of that for any rescue team to travel to the site of the emergency. Moreover, my setup does not let me communicate the nature of the emergency in any way. Eventually the battery on my system will expire, and it costs a fortune to replace because the unit is sealed, so I was checking out small satellite phones like those from Garmin. They cost a ÂŁ350 for a system (plus some painful monthly fees) that allows you to send text messages. If Apple adds satellite connectivity to the iPhone, even if it is just texting for emergencies, then I would save myself a great deal of money by simply upgrading my iPhone. The same holds true for anybody who visits rural and wild areas, and some who would use this as a backup if they were sailing the ocean. Also, as people have pointed out above, this could be useful in natural disasters like floods, blizzards, fires, etc.
Now, if Apple would just formally kill off their CSAM spying software proposal, I'd start saving up for a new iPhone on the hope this new feature will actually come to fruition.