We may be fed a tale of ever expanding life expectancy, but while average lifespans may be rising maximum years are unchanged. If we want to keep extending the clock we need more than antibiotics and nutrition.
The easy work is done
While improving living standards and reducing infant mortality was not an easy job in itself, it extended years without fundamentally changing human biology. The incredible changes brought by the 20th century yielded longevity — but predominantly did so by lifting the majority closer to those luckier few. Even in the ancient world individuals seemingly lived over 80 years old; it was simply a rarer event to do so. You were significantly more likely to be felled by a disease beforehand, and many never reached such an advanced age as a result.