It really depends on where you live.

Not really. For example yes nyc has a low case incidence rate, but the virus is blowing up in many other parts of America. Even during this period of relatively low travel it’s safe to assume there are people coming into nyc from around the country every day. Testing is delayed by 8-17 days, so the public health data is dangerously out of date. To be safe right now means isolating.

Isolating is not necessarily more healthy, nor required everywhere right now.

For example in Norway, you don't have to isolate. The numbers are relatively low, the clusters are well tracked, the few travelers from dangerous countries like USA have quarantines. You still have to be careful of course.

To compare the Norwegian response to the American response, and to presume any competence in America, seems quite irrational at this point to me. There are people out mixing in nyc in ways that will allow virus transfer when it gets back here one way or another. As time goes on more and more people are out. If there was no testing delay I would absolutely agree with you, but we are looking at a week minimum delay. The conditions bear more and more similarity to March. De Blasio (who deserves no respect on how he has handled any of the problems facing nyc currently) is trying to reopen the schools. Maybe only one of these things would be ok, but this is a disaster in the making.

I'm thinking he is (as am I) in the US. We sometimes forget there are countries outside of this one.

If all those things were being done in the US, then you wouldn't have to isolate. But they're not.