This is not true. An average adult lives longer still just not by that much. Whole bunch of deadly diseases or injuries are not deadly anymore. The work got safer and injuries happen significantly less often.
What did not changed is maximum longevity people have assuming they don't get sick or injured.
Neither accidents nor sicknesss are noise. Both are and especially were fairly frequent reason of death. And whether you survive them has a lot to do with both medical and social improvements.
What did not changed is maximum longevity people have assuming they don't get sick or injured.