I think it's good advice even if anecdotal. At least I do not think it hurts. My own observation is that almost everyone gets hit hard by the 80s. A lot of people in their 70s are spry, but it seems like damn near everyone gets significant decline in their 80s. A few people make it to the 90s, and some are even relatively spry, but my own anecdotal observations are that it is fairly rare. My grandparents both made it into their mid-90s before the decline really took hold (and then it was fast) but they were outliers. Both of my own parents made it to their mid-80s and that was it.