Exactly. These people keep working at 80 because their pensions are shit, not because they enjoy it. Well, some of them do enjoy it because they don't have any hobby and don't know how to enjoy their retirements, they just know how to work, which is equally depressing.
I live in Japan and heard the same story from Japanese people, so sadly it seems not to be a myth. It is not super common either, but it is pretty sad that it happens at all.
At least in my culture, older people feel productive by focusing on their family and friends. I prefer that to working until you die, but to each their own.
