indeed contagiousness is different from mortality, but think of it like this, if more humans are infected at the same time, it'll overload the hospital capacities,
this will
1- make it impossible to ensure proper care, since the hospitals will be overwhelmed.
2- also impact patients who require treatments for other illnesses, since systems will be busy and overloaded with the covid-19 patients.
Hospitals in the US are so lacking with patients that they are furloughing and laying off doctors and losing money. They never were overwhelmed and would not have been