Would we truly be "unable to live"? I shudder at the thought of "if I didn't have this one thing I wouldn't be able to live" what happens if I wake up tomorrow and that one thing breaks down, and isn't replaceable? Will life end b/c I don't have it?
It's an interesting question because on one hand, we believers know that we technically have all we need in Jesus, at least for eternal life.
But this raises the even more interesting debate between what truly qualifies as needs or wants, or necessities vs. creature comforts in our modern world.
One of the first things your post brought to my mind was electricity. Sure, people lived without it, and plenty still live without it today. But I would have to argue that in developed countries, it's almost a necessity.
I live in an area that has been plagued by both bad weather and attacks on power plants. Not long ago, my electricity shut off (and of course, it's the middle of winter,) and when I called, I was informed that somewhere between 40,000 - 60,000 people were without power. I was already trying to plan out what I would do if the power was down too long and it got too cold.
I live very close to a hospital and large cluster of medical buildings and facilities, so we are extremely blessed to be on the same power grid as those buildings, and it's considered a priority area for restoring power. They had it up and running again in our immediate area later that day. Many others were without power for nearly a week, and my heart goes out to anyone who has to survive the bitter cold (whether sheltered or not.)
Is electricity absolutely necessary? Will life end because we don't have it? Should we shudder to think what will happen to us if it's suddenly taken away?
For some people, I would argue that the answer is yes, as I have no doubt that some of the people in the medical facilities behind me may have perished or wound up in worse condition if they hadn't gotten the power back on as quickly as they did.
(I understand places like this have back-up generators, but imagine your loved one, who requires electronic devices to stay alive, being in a hospital for a week without electricity.)
If it would have been my parents, I would have been a nervous wreck.