I'm 68 and annuitized my after tax annuity from TIAA-CREF last year. For me personally, and I'm sure there are others out there that feel the same, it is a relief not to have to worry about how to invest a lump sum of money. I remove that headache by having a pension that increases 1 to 4% yearly, due to the nature of my particular pension.
I am encouraged to stay healthy by doing this. Again, for me this works- I am being paid a "salary" to stay healthy, and fit. It is a motivator for me. I'm not sure if I would feel the same way if I had a large sum of money to play around with, and get income from that.
I still have a pretty good chunk of other investments with TIAA-CREF to play around with and take chances, knowing that I won't be burned to much if I lose money. For me, the "pension" allows me to concentrate on having fun, relaxing, and just enjoying old age. Others my find playing around with the bond market and stock market fun. I really don't.
Rob