This apparent paradox is caused by a slight difference between the massive increase in risk of death increasing with age and nearly as massive decrease in risk with full vaccination.

Nearly, but slightly smaller.

For a 70 yo person, the increase in risk from age alone is 32x as compared to 35 yo.

Double vaccination reduces that risk by 20x.

This is in details explained here:

https://uk.news.yahoo.com/most-covid-deaths-vaccinated-heres-102424441.html