As to the importance of testing, this is a transcription of some comments from the Mayor of NYC at the beginning of a broader commentary.
length of video: 8:57
The transcript below the video is only for the first 1:17

NYC Mayor Bill de Blasio announces increased production of coronavirus test kits
Apr 14, 2020

“The number one issue from day one has been testing.

“When we started fighting the coronavirus here in the city, we said we needed the federal help with testing. It never came.

“We have scoured the world looking for test kits on the open market. It's been extraordinarily frustrating, we've had so many good people searching everywhere just to buy the test kits… to get a reliable supply, it has not been possible.

“So, over months now, the place we turned to help, Washington DC - we never got a straight answer, we never got a consistent approach, and we wondered, when would the day come when we could actually get the test kits we need so we could start on that road that I talked about a few days ago, from this widespread transmission of the Coronavirus to low level transmission and eventually no transmission. To get there, you must have testing in large quantities, and we knew that, as recently as yesterday, we did not know when and where we would get those test kits.

“Now, we’ve had one breakthrough on the open market, and then another breakthrough right here in New York City and then I’m so excited to tell you about this. [...]"