1. It won't be just the over 70s if no one can get proper treatment at a hospital for their traffic accident, chronic disease, hernia ...
2. Severe cases include a wide variety of ages. The over 70s are just the first to hit the ERs
This is complacency. A lot of under-50s, particularly male smokers and others with weakened lungs or immune system, are at risk; even fit under-40s can require weeks of externally-provided ventilation to survive.
People who are over 70 dying in large numbers is a humanitarian crisis, not an economic one.