Here is why I don't think they are enough.
1) Isolation is not uniform across the country. Some people are working from home. Others aren't. Some schools are closed. Some aren't. Some trips are cancelled. Some planes are still flying with some people. There are still large areas of the country where it's spreading with little or no isolation. The cases there will grow, and walk across state borders.
2) It's not enough, yet. We have some isolation in some spots. But there's not yet even one single spot with measures as drastic as are needed to stop this.
Italy has had stricter measures than the US in place for a little while, and the number of new people seeking hospital care per day is still growing.
The places which have successfully turned this thing around have put measures in place much more drastic than the US, and on a consistent national basis.
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I guess we disagree about the US being more isolated than Italy or not. I think Italy has more isolation in place. Please let me know in what ways things here are more isolated than Italy.