My (current) youngest child should leave home when I'm 58. I plan to get a paying job then, and work until I die. If I have another baby, obviously that will change the numbers :-).
If any or all of the dire predictions turn out correct, then it will simply prove that it was unreasonable for people to expect up to 40 years of post-work idleness at *somebody's* expense.
(Space for Captain Obvious graphic here.)
Darn good point.