I feel bad for these people. I really do. The writing has been on the wall for decades that coal is a bad horse to back, and poverty is keeping their options limited.
This is another example of why we need a better social safety net. Let's retrain those people with skills that will better suit them and their families. There is no reason that they should suffer with this dead-end life/career/poverty.
They are also attached to the places, and do not wish to leave. Retraining for new jobs in cities, or even different rural areas, means leaving longstanding family homes.
I need to note that I'm not an expert. I'm speaking here thirdhand at best. But I'll note that in the last Presidential election, when asked to choose between a candidate who promised retraining and social safety nets versus one who promised to re-open the coal mines, they overwhelmingly chose the latter.
That's kind of a distorted way to look at it. People do leave, and then they aren't included in the population that's under the microscope. So the remainder is always being distilled down, no matter how bad things get, until the outside world decides they can be ignored. Same thing with farmers in the 20th century.