That's answered in the article that people are taking proactive measures because they don't want to expose themselves for the sake of herd immunity. New York C

That's answered in the article that people are taking proactive measures because they don't want to expose themselves for the sake of herd immunity. New York City has an estimated 13% of people have had Covid-19. That's nowhere near the 50-80% needed mentioned in this article. Just the back-of-the-envelope time and scale needed for herd immunity shows how far away we are. The US would need 200 days of 1 million new people each day catching it to reach herd immunity. That's with the most generous assumptions about reinfection. Any health system (especially the US') would crumble under that load.