There was no need to delay social distancing on account scientific uncertainty over the practice. We already knew social distancing was an effective method of preventing spread. Heck, we've known it since the 1918 spanish flu, since quarantines themselves begam. (and still, it was delayed, still is delayed in some places)
The point is that there is a resource bottleneck on "action". There are limited resources. You qualified your own statement as necessary action. How do you know what is necessary? Options must be weighed, the most promising chosen, as many, but not all paths can be pursued. I'm not saying "do nothing", I'm saying that we can't do everything. And then, yes, in areas of great uncertainty, where wrong action can cause more harm than choosing to wait, then we should not take action merely for the sake of "we can't do nothing!!!" emotional response to the crisis.
The point is that there is a resource bottleneck on "action". There are limited resources. You qualified your own statement as necessary action. How do you know what is necessary? Options must be weighed, the most promising chosen, as many, but not all paths can be pursued. I'm not saying "do nothing", I'm saying that we can't do everything. And then, yes, in areas of great uncertainty, where wrong action can cause more harm than choosing to wait, then we should not take action merely for the sake of "we can't do nothing!!!" emotional response to the crisis.