There is another factor which I haven’t seen included – active old age. For those of us with enough money there isn’t a problem of running out of money.
Steve mentioned that his breakeven age for taking early payments was 88. For many, the extra money would be nicer to have at 80 rather than 90. I’ve observed that my relatives and in-laws slowed down considerably after age 90.
In many cases (most?) delaying allows you to spend more money in the early years because it reduces the chance of portfolio bust as you get older.