Some of the "on meds in their forties" stuff is not a matter of our bodies being too frail to age to 100. It's heavily influenced by lifestyle, such as
@Britsmoothy sucking on LRBs. Type 2 Diabetes was a rich man's illness 200 years ago. Now it is found in children of the poorest families. The extraordinary concentrations of non-nutritional "food" in the modern western diet, chemical exposure, et al has exacerbated the level of health risk in the modern human body. This is not to say that folks in the past lead healthy, ideal lives. Merely that this is not a case of "everyone has lived life on the same foot and we are doomed to early death without modern medicine". Such is partly the case, but not the full story.