Psalm 90:10
The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labour and sorrow; for it is soon cut off, and we fly away.
All the surgical advances kept a kid with pyloric stenosis alive. All the cardiac surgery advances kept a kid with Tetralogy alive. All the neonatology, critical care, neurosurgery, nutrition, etc., kept premature kids alive.
No way was it just sulfa drugs and penicillin.
In fact, the first antibiotics, penicillin and sulfa drugs, were not available until WW2... the elongation in life expectancy started well before 1939.
It was a worldwide army of people working their behinds off, caring for the sick, and doing research on millions of different things.
Not just antibiotics.