Countries aren't full of old people because of healthcare, they're full of old people because birthrates plummeted after one of the largest generations ever was born in the post-war period.
Countries aren't full of old people because of healthcare, they're full of old people because birthrates plummeted after one of the largest generations ever was born in the post-war period.
Causality is complicated and probably impossible to untangle, but the vast decreases in both infant/early child and maternal mortality played a huge role here.
If half your children didn't die by age 20 (or 5), it was possible to have much smaller families. Industrialisation and urbanisation made children net liabilities rather than household assets (providing labour even at a very young age). Financialisation of real estate along with the rest of the economy made earning and saving money critical, and made non-cash or low-cash lifestyles highly marginal (self-sufficient existence or providing many goods and services through the home directly). All that in combination with improved adult lifespans meant that the demographic pyramid consolidated at the bottom and expanded at the top. There are still countries where this isn't the case, most notably now in sub-Saharan Africa, particularly where HIV/AIDS remains endemic:
Contrast Tanzania and Italy, for example:
<https://www.indexmundi.com/tanzania/age_structure.html>
<https://www.indexmundi.com/italy/age_structure.html>
Turned out that if you gave people choice they'd rather not have 7 kids! Surprise surprise.