But... we did flatten the curve enough to avoid overwhelming the healthcare system. To suggest it wasn't enough now is moving the goalposts.
Well, the curve had somewhat flattened (but was still trending upward among the noise) before reaching the point of overwhelming the system before we started reopening and it unflattened. I think it was premature to say that it had been flattened enough to avoid rather than delay that outcome, though it's kind of immaterial anyway since we abandoned the effort to keep it flat and are heading straight for overwhelming the system.
The fire department was able to get that room where the fire started mostly put out, there's still a little bit of fire in the hallway, and they start putting the hoses away.
"There's much less fire than when we started, and people were getting really angry about the water damage to the surrounding buildings. We are all done here!"
Would you be happy about this situation, wouldn't you point out that even if there is less fire, nothing else has changed about the situation. Fire still spreads, it can still catch the building on fire, and that fire could still spread to the surrounding buildings.
The problem isn't over yet, and if the whole point of suffering the water damage was that my building wouldn't burn down, well now I have water damage and it might still burn down.
Prolonged lockdowns have costs too, it's just not politically correct to compare them to peoples' lives so people like to ignore them.
Can people really go 18 months with no employment? Can students miss 18 months of schooling? Can people go 18 months without other medical care? Can housing go 18 months without upkeep because the landlords have no money since they can't evict rent nonpayers?
A lockdown that extended is not feasible, even before you get to any discretionary economic activity.