I don't think this is a fair comparison. It's easier to move and retrain nowadays; there's also more kinds of jobs. These things will probably become even easier with more automation.
The moving thing is not true; or if it is easy we're at a historic low of people doing easy things (at least in America)[1]. Internationally, it sure looks to me like folks want to tighten borders and reduce international movement [no cite; just vibes].
As for retraining, I am skeptical. I think it, at best, puts an older demographic in competition for entry level jobs, and generally at a disadvantage[2].