What we know is that we are pursuing the best path toward preserving the public from the physical effects of the virus. There is a moral conflict about whether preserving the economy over the physical effects of COVID is the best course. As of now, America has chosen to sacrifice the economy for preservation of health. Almost every other country has made the same decision.
Social distancing does seem to help and appears to have made a difference in Washington and California--states that had the two first COVID clusters and states that took the earliest action.