I think you are missing the point of the discussion. The idea behind "just retrain" rhetoric is effectively "new technology won't destroy people's quality of life because they can just retrain!". If quality of life isn't maintained, then there is no reason to retrain at all, people can just get a minimum wage job and live in poverty.
The rhetoric was a lie. Capitalists lie. That new technology always creates a surplus of newer, better jobs and quality of life always improves for everyone was a lie. That you can "just retrain" and everything will remain the same was a lie.
Even if you "retrain" your quality of life will go down because the market value of your life will go down as automation and AI improve, unless you're a member of the capitalist class. Which, if you need to work for a living at all, you aren't. No matter what you do unless you're personally wealthy your quality of life will go down. That's just what an efficient market does to most people, and AI is going to make the market brutally efficient.
I wonder how many sectors this will have to happen to until workers realize that nobody's safe. I was shocked to see journalists at major firms peddling the 'just learn to code' line a few years back, given how much their industry had contracted in the decades before.
Quality of life during the Industrial Revolution dropped considerably for most of the working population, but afterwards saw big improvements. You seem to be implying that life now is worse than before the IR. Are you? If not, in what way was the loss of jobs to mechanisation then more acceptable than it is now?
The overall quality of life improved through and thanks to IR. But the quality of life of the people most affected, and their children, and their children's children - did not do so well.
Technological progress automating away jobs lifts humanity as a whole, but it absolutely fucks over the people whose jobs got automated away, and the families of those people, and the communities they live in.
