Your comment implies that "do[ing] this three times more" would be very difficult. That's totally incorrect. As the level of immunity rises, R0 goes down naturally. The effect is huge at even 20%. Giant at 50%, etc., especially with moderate social distancing. Moreover, there is every reason to believe that some people are just naturally resistant/immune to the virus. I believe Bergamo never got above 57% sero-positivity and even the USS Rosevelt was around 60% sero-positivity. It seems impossible to believe the other 40% weren't exposed. If (okay a big BIG if) 40% just don't ever get COVID, and 50% get it but have mild moderate symptoms (the data strongly supports this), NYC is basically done with this emergency.