This is a piece of the retirement puzzle not mentioned here. Healthcare.
How much will the starting cost of Medicare increase, past 65, while you are waiting for the SS build-up? Once you start Social Security, it can't increase by more that the SS COLA. But it CAN increase greater than the SS COLA, in the gap between 65 and when you take SS. If it does, it eats away at the 8% a year SS boost for waiting.
And this is not including the "high retirement" extra price for Medicare. (This can get <real> nasty with IRA/401K RMDs. You may have to take out so much that you get kicked into the "high retirement earning" extra Medicare cost.)
There are multiple games to be played here, and they all interact with each other. . . .
(Which is why I plan to work until 63 1/2, at a minimum . .
)