People keep wanting to stay open 'for the economy', but if everyone outside of essential personnel were to stay home for three weeks, the virus would be dead because it couldn't find new hosts. That's something to think about. Three weeks of complete inactivity versus a year or longer of everything only half functional and lots of death and discomfort. Naturally, society chose the latter.
Edit: I don't mean to say the disease passes in three weeks, but it does come out after three weeks and if it doesn't, you've probably already wrecked it, so if there were no contact between groups during those weeks, you can basically identify everybody who's carrying the virus.