I agree, so let's assume the US doesn't intervene at all.

Exponential growth is occurring because the median person is infecting more than one other person, which right now is coming from people not knowing they have the virus and not worrying about getting the virus.

Even without government intervention, as cases increase people will start taking this more seriously and the exponential growth will stop. Even if you don't have symptoms but have the virus, you aren't going to that concert or that vacation because you don't want to catch the virus from someone else.