Well, if we do nothing and simply let people have it a die, about 2% of population will die (I doubt it will be 5% since the mortality rate is overestimated due to many minor diagnosed cases), but it will be over in 3 month as everybody will get sick and all recovered people will be immune. Yes, it is a lot. Yes, it is human tragedy. Yes, it is comparable to WW2 death rate. But in WW2 the dead were young people and it lasted for many years, and the war required lots of resources. With this virus, it will be mostly elderly who will die and it will be over on 3 month with very little resources spent. I know, it may be sounded cold, but such death will actually improve the economy since the average age of survivors will be lower.
On the other hand, if we try to fight this virus, it will take about an year to develop a vaccine. Social distancing must be practising for a year, with full isolation (as now) at least for 3 month (plus maybe another 3 month once the second wave will start after isolation stops). 80% of population will still get sick, but because of the flatter curve, better medical services will be available and mortality rate may be down to 0.5%. So, we save lots of life but get a war-type effect on the economy (lots of resources).
The trade-off is simple: save 15% of the older generation at the expense of huge unemployment, general population health decline (due to more unhealthy food that will be affordable for people and poor housing), and much less bright future for our kids. I wish the government finally call spade a spade and tell us what we expect to lose and what we expect to gain by trying to fight the virus the way we do now. So far we hear lots of health suggestions but not an estimate of how much it will cost the economy. And, as history teaches us, money is more important then lives (otherwise there will be no wars)