That's an interesting take as well. On the Bogleheads VPW thread and model, they advocate buying a SPIA at age 80 as a floor, i.e., to cover the essentials forward. Based on your idea, it really is a timing thing, i.e. when would you really need it. In the VPW model, you delay purchasing the SPIA so that you have a good 15-20 years of frankly higher variable withdrawals when you are most probably able to 'use' it.
One could also think of any pension, and especially a COLA adjusted one, as a SPIA of sort. Any pension takes quite a bit of pressure of the requirement of the portfolio to perform well. As I've been calculating what I could spend in my soon sort of early retirement, I've realized that my pensions and SS will allow me to have a much larger spending ability cushion over my truly necessary lifestyle costs.
As a tweener (born at end of Boomer/beginning of Gen Z), I've had to adjust quite a bit to the changing expectations for retirement funding: defined benefit pension, defined contribution plan, no plan-fund yourself. Fortunately I have elements of all of those in my retirement scenario. When I was transiting through my work-life, I tended to not pay attention to the pension part of it thinking I had to go the 'no-plan-fund yourself' route. In retrospect, I am very fortunate - but didn't realize it. However, if I did have to rely 100% on the 'no-plan-fund yourself' route, I would probably look at the SPIA for covering basic life costs combined with SS - the 75% of projected version - and then the rest would be invested for non-essentials.
As many have said on this thread, these are complex situations with time dependent variables that call for more complex risk management strategies. To each his own. In general, I would say once you've figured out your risk tolerance, try to find the least inexpensive way of covering that.
