Even if that is the case, jobs now change at much more rapid pace than in the past. It used to be that if you trained and worked as a blacksmith (or whatever),

Even if that is the case, jobs now change at much more rapid pace than in the past. It used to be that if you trained and worked as a blacksmith (or whatever), you could die a blacksmith. It was their kids that would have to do something else. Which isn't too much of a shock to the system. This is no longer the case. Now someone within a single lifetime can go through multiple job creation and destruction cycles. So it'd be helpful to have a floor to help deal with the transitions and provide a buffer.