Slower population growth is Not a reason why communicable diseases like pneumonia kill fewer people today than they did in the past, this is because in present times irrespective of the population growth, newer approaches have been introduced to improve quality of life and hence reduce the risk of communicable diseases.
Approaches like; continuing medical advances, improved living conditions, better preventive treatment. Etc.
because don’t Know that you are making them proud, all parents are like that and no one could change that answer. It also could be that you are old enough or a teen.