The more reason to educate people on that front. Don't rely on your single piece of tech in your pocket to work all the time. Society ought to reacquire a bit of resilience on that front.

Need to do critical patient care while commuting? Surely you will have made sure to bring a dumb phone with you as backup, if you are really that critical a resource (after all, your battery might be dead, someone might have stolen your fancy Iphone, etc.).

Time sensitive family issue? What if you turned your phone off to read a book? Are you the asshole now? The train driver might have been stopped at a red signal in the Schipholtunnel; not much of a chance of getting a phone signal there. Is he now endangering people by depriving them of their umbilical uplink?

What if the time sensitive family issue happened while you had your phone turned off for some intimate private time with your partner? How will you ever forgive yourself?

The key takeaway here is to understand that there is no such thing as being available all the time. So don't expect it, and don't feel guilty about not providing it.

There are all plenty more of those convoluted minimal chance scenarios you can come up with, but these hold true for anything people around you do.