John Galt, more thoughts on your questions
Scott Burns seems to be the most educated & pragmatic writer on the SS debate. I'm taking most of my numbers from his articles, including the presumption that delaying benefits until age 65 involves a 14-year payback to age 79. (I've seen other numbers but this one is the longest.) I have no idea what the payback is if I delay until age 70 but if it's less than 90 I’m probably still in the game.
First, I'm still 19 years away from a SS decision and no doubt I'm going to flipflop at least once before then.
Second, I'm in excellent health from a long-lived male line. My grandfather made it to 97 (although the dementia kicked in at 84) and my father shows every sign of doing the same (hopefully without the dementia). My other ancestors either worked hard at killing themselves (alcohol, smoking) or lived into their 90s. Being trained as a nuclear engineer, I tend to obsess a little over my lifestyle & nutrition in order to optimize my chances. (That's a lot easier in retirement than on deployment.) I also have a loving spouse and a kid who are proud to nag me as much as it takes to stay the course. (It's hard to believe that this makes a statistically-significant difference, but they assure me that it does.)
Third, at this point in my life it's hard to imagine that the small amount of SS that I'd collect between ages 62-70 will make a difference in my life. Sure, it's 27% of my pension now but when I'm eligible for SS my spouse will be drawing a heckuva pension of her own. My SS will only raise our income by 8-10% before taxes. It'll certainly be a taxable difference, and an investable one as well, but it won't change our lifestyle.
Fourth, all of us know that we should grab whatever money as early as we can, invest it wisely, and let it compound for decades in low-cost low-turnover stock index mutual funds. We also know that we could take the gov't's return of our hard-paid tax money and fritter it away on longboards. I doubt that most of us survive that cognitive dissonance to actually follow through on the more appropriate course (whatever that is). I, of course, will make the financially correct choice, no matter how nicely that custom longboard would carve on the waves. Sure.
Fifth, I see a lot of spouses who take themselves out of the workforce to raise a family while blindly trusting their working spouses to "take care of them". (Some of these people are men, most are women.) Given my fourth opinion, I feel that those families have to seriously consider delaying SS benefits. Especially if the working spouse doesn't outlive the 14-year payback, their nonworking spouses will probably earn far more in higher survivor benefits than their deceased spouse would ever have drawn.
Sixth, I think that further SS reform will pass by the boomer generation (birthdates as late as 1964). In other words I think that "I got mine." The system can't survive its present mutations, but the only people with reason to fear are our kids. If I do see a change coming, I'll have plenty of time to change my decision (and to try to have AARP get my elected politicians to change theirs).
So what am I gonna do? Today I'm going to grab every penny as early as I can and invest it. If nothing else it'll self-insure my LTC costs. Hopefully by 62 I'll have matured enough to have given up my hobby stocks (including shorting & options) and I'll put it all into a good stock index fund.
No doubt the closer I get to your point, the more I'll feel as you do. Unless technology makes some incredible longboard advances in the next two decades?