An observation from some things I've seen lately. I'll explain.
I work in a public sector organisation that employees highly qualified and very well paid professionals alongside support staff on not much more than minimum wage and those in between.
Part of my role is managing sickness absence. What I am seeing lately is that the professional types, despite doing what are generally accepted to be stressful jobs, on the whole, stay well until well into their sixties, although many do retire earlier simply because they have the kind of pensions that make that possible.
People in the more lowly jobs are often genuinely finished by their mid-late 50s. Just worn out and suffering from multiple health problems. Perhaps because of their lifestyles or maybe from just having harder lives (not necessarily harder work lives, but getting by is just generally harder for them). To have to go on to 67 is just absurd and very few do, with ill health retirement common (so the state is paying anyway).
I can't begin to imagine how similar people manage in genuinely physical jobs, in construction for example.
Is it more common for working class people in their 50s to be worn out, or perhaps more comfortably off professionals retire before they get to that point so I don't see it?