Lamplighters are especially useful to consider here.
How many lives has electricity saved? How many ICUs can operate continual machines because of it? How many people at risk of heat stroke can run AC in summer because of it? How many transplants and temperature controlled medicines got delivered because of it? What about its role in food safety? What about timely communications of life saving information, like those lost at sea asking for help, or severe weather alerts advising others to shelter? That's just the beginning, it seems incalculable really.
That lamplighter should have had a society willing to catch them during the transition. But imagine if it solved this problem by holding that one person's job sacred at the cost of millions of other lives instead.
It's absolutely good and relevant to worry about individual cases, but it seems like society is better off if we allow jobs to adjust to the actual current needs of humanity, rather than holding them fixed. Then we just also try to do our best to take care of as many of those who fall through the cracks as we can.