That's the ideal, in reality too many of these people live in areas where there are no other opportunities. They are also often fed the line that the job can be brought back.
Put simply, we've observed generational shifts to higher-valued jobs in urban areas. A farmer, coal miner , etc who loses their job today is unlikely to re-skill & move to other industries
Don't confuse what is the current outcome with what has to be the outcome. Those individuals might not reskill in todays environment because of a combination of receiving an insufficient amount of the value they produced in their wages (preventing them from having the resources to retrain themselves), as well as social programs for reskilling being severely limited in both funding and how they constrain how and what skills are trained. (preventing gov't resources from retraining workers).
Neither of those has to be a forgone conclusion.
https://www.wired.com/2015/11/can-you-teach-a-coal-miner-to-...
I'm saying it can't be done at the current rate of change. There are just too many people caught off guard, compounded by technological & automation adoption too rapid for them to adapt.
I think you may underestimate the scale of the problem. Why so many people in the center of this country voted for a catchy tag-line on a baseball cap.
It can't be this program that gets hauled out into the light occasionally, constrained by industry, geography, time, and whatever else gets thrown into the mix to constrain the program cost - it ends up costing us all more (in money and social instability) to not address the problem.