It is most definitely going to be the unemployment line. When in the history of productivity gains, has it translated to more time for people to do other things that are not work? It always translates to more profits for shareholders and bigger pay for executive class, followed by more work for half the workers to fill up the time opened up by the said productivity gains, and unemployment for the other half.
200 years ago, 80% of Americans worked in farming. 150 years ago, that was still over half. It’s now under 2%.
If you’ve seen the work hours and work ethic of farmers, it’s safe to say that most of those people got other jobs that take far less work than farmers did/do.
Closer to our field, I think we’d have far worse work lives (fewer of us employed and much lower pay) if we had to code everything in assembler still. The creation of more powerful abstractions and languages allowed more of us to become software devs and make a living this way than if all we had were the less productive tools of the early days of computing.
Many people lost their livelihoods though in each transition. I find each life valuable but that's just me - yes we are better in aggregate long term but in some ways it is paved with their sacrifice.
If we can find a way to support those displaced even that would be a much better start. e.g. re-education funds, training schools/government run apprenticeships on projects, etc. Especially if the scale of the displacement is large. We all only have the one life IMV - its about giving those lives the opportunities to pivot. Ageism, and gatekeeping will stop many from changing careers.