Easy to discern ChildCarter didn't read that whole Guardian article. And absorb Yank's obvious point. Spikes in the 20-40 demographic cause major spread. Who is out and about the most? Who is working in senior care and hospitals and rehab centers?
We know the virus was in New York and spreading months before the first official case was discovered. One estimate I saw said New York City may have had as many as 11,000 undetected cases before March. The fact that it was here and spreading without causing alarm on deaths (outside of the cases that were probably misdiagnosed) says that it first hit the younger and less vulnerable in the population.
Of course, we weren't taking measures to limit the spread then, and those young people had no way of knowing they were infected before spreading it to others. But what we are seeing now is likely a repeat of the same thing that happened the first time, not some change in conditions that in and of itself limits deaths.