Those jobs are often not easy to replace financially for the people working them. It involves uprooting their families, or being away for weeks at a time, working in the natural gas industry or similar, and they still don't make more than they were making in coal. I grew up around coal country Appalachia. Making $50,000 per year in a coal mine in the early 1990s, anywhere in Appalachia, was a financial godsend for those workers. I knew a lot of families that it provided a solid middle class life for, people that otherwise were going to be stuck working low wage jobs in those regions, if there were any jobs at all (and it was a hard, dirty, unhealthy, dangerous job; they all knew that).
A typical Sears worker has plenty of other opportunities at comparable or higher pay. There isn't a shortage of $13-$15 / hour jobs in the US, particularly in the locations where most Sears stores operated historically.
It's awful because real people are losing their jobs and probably don't have the best prospects. It's necessary though. It's one of the reasons a good government has social programs to support those whose jobs become obsolete.
One significant difference: coal employees are concentrated in a relatively small number of communities, which means that those communities are collectively suffering greatly, and the employees have fewer opportunities because there are no more jobs locally.
Farriers and ice deliverers were relatively evenly distributed, lessening the overall community impact and making it much easier to find a new career.
You should go read about the Battle of Blair Mountain and the Coal Wars. Big Coal more or less committed genocide in Appalachia and not only got away with it but had some assistance from the US government. That's how powerful they are. The number of senators these states have is pretty irrelevant in the grand scheme.
https://www.washingtonpost.com/news/wonk/wp/2017/03/31/8-sur...
You could for instance encourage solar companies to hire ex coal miners and pay them good wages.
When shifting an experienced miner to the natural gas industry, the problem isn't education, it's replacement pay. They're usually technically, industrially competent people, and are well suited to the oil and natural gas industries as far as ease of skill adaptation goes. It's something our government/s should be pursuing aggressively (except usually the states where the coal industry exists don't want to go against those jobs and actively encourage that shift). If done correctly, you could make the job shift from coal to other energy industries far easier, buffering the labor hit, and drain the coal industry of the labor it needs to operate (accelerating its demise).
There's reasons the whole "just replace coal jobs with solar jobs" thing has never played out. It's not for a lack of trying or because nobody here ever coming up with the idea. It's because the powers that be sure as hell weren't gonna let it fly.
(TVA continues to be the least green utility in the South btw. Promotion of the welfare of the people of the Tennessee Valley my ass.)