Quick question ... wouldn't a more appropriate response be to self quarantine those age groups most at risk?
It's like the flu shot. One big reason to get the flu shot every year, even if you never get the flu, is because controlling it needs to be a community effort. A big vector for seasonal flu is young, healthy people with subclinical infections. They never develop any symptoms, or maybe think it's just a cold, so they keep circulating in public and blithely spreading it to others.