"Many more people are living in to their 70's, 80's and 90's than previously in human history."Correct, though largely (not entirely, but very largely) because the proportion of people living past age ~3 has skyrocketed. Correct for that factor, and our life expectancy is actually lower than it was in, say, mid-Victorian England.
(Note, as well, that I'm referring to life expectancy and not, say, the potential maximum human lifespan).