[klmadfejno]

The median age of New Yorkers is around 36 vs. the median age of covid patients of 63. That's a huge difference. The point you seemed to be making is that the demographics of COVID deaths are close enough to the demographics of the general population, implying that these demographics aren't indicative of anything. That is not an accurate statement.

The usage seems fairly obvious to me. The risk to young health people is somewhere in the range of 20-200x smaller than someone who is old and in poor health. It's not a surprising claim, but it's clearly a useful thing to know for medical planning. It's also useful at an individual level to get a sense of their personal risk level. Finally, it is useful in understanding past outcomes. If two different countries have different mortality rates, but also different demographics, and both of them had similar mortality rates normalized to those demographics... that's pretty useful to know.