Why do we value infants (and hypothetical future ones) over adults?

I had a college roommate from South Korea who once told me one of the differences he’d noticed between his culture and American culture is that if there was a building on fire and the rescuers had to choose between saving an infant or an adult, Koreans would choose to rescue the adult before the child, as the adult has already proven they possess whatever skills are required to ensure that they lived to adulthood, whereas a baby has proven no such thing - and besides - you can always make another baby. It takes a lot more resources and investment to bring one to adulthood.