Didn't most people live to their 60s if they survived childhood and pregnancies?
There always are old adults present, but they are rare.
From your nickname, I gather you are a Czech. I can link an article about analysis of an early medieval cemetery in Rajhradice to you. 244 buried people, 220 skeletons were successfully analyzed for age. No one over 60, eight people over fifty (almost all women).
https://karolinum.cz/data/clanek/5704/Praehist_34_1_0007.pdf
Life expectancy at birth was around 30-35 for at least the several preceding centuries in Europe.
https://publishing.cdlib.org/ucpressebooks/data/13030/tf/ft0...
Basically, until the 19th century, between 25-35 % of people lived to be 60 or more. In the 20th century, this grew rapidly up to 90 per cent.
80 y.o.-s would be very rare even in the 19th century, while now about half of the population lives to be eighty.
Note that this is the Modern Age. In the Middle Ages, survival would have been worse. A more primitive agriculture, less developed long distance trade and fewer staple foods (no potatoes etc. in Europe prior to the Columbian exchange) would result in frequent famines that took the infirm first.
Things would be yet worse in the Early Middle Ages, the period of frequent nomadic incursions and warfare in most of Europe. At least the High Middle Ages were relatively peaceful compared to the period before.