The problem is that as the lock downs work, it's easy to lose sight of what could have been, they stop it getting out of control and it still looks bad as there was the initial clump of infections, but the abstract hundreds per day that are dying are still fairly remote for most of us as only 1%-2% of many of our populations got infected. One can still throw around figures of "it's less death than this" or "the lock down is causing X amount of economic + societal misery".
The scientific consensus seems to be that if the disease had just been left to run it's course, even with people being moderately careful given how infectious it is, it would have caused huge death figures. Perhaps that might be proved wrong when we see some countries that simply socially distanced instead of locking down, but was it ever worth the risk?
All these "well, it's bad, but look at the economic damage" have to be weighed against what could have been, not what is. And we just can't imagine this, we can say it, but how many of us can imagine 10,000s dead per day?
Your Aunt dead, a colleague dead and your best-friend's Dad dead, your Butcher's Grandmother dead, your barista's sister dead, a teacher at your primary school dead, your football team's goalie dead. And more, and more. Of the few hundred people you know you would have known several people who would have died, or the thousand or so you are a 2nd connection to you would have heard of many deaths.
On top of that all, New York and the UK only really have Italy and Spain to look at as any sort of predictor. They now have to watch just two countries to see what happens when they start easing the restrictions, and due to the massive lag between infection and hospitalisation/death and insufficient testing capacity, it's all still guess work.
Lift it a week or two too early, and you might have to go into another lock down in a few months time.