Well, there might have been a few cases. But the fact that 95% of infected people are invisible makes it look like none.
Imagine two people had Covid in your town without anybody knowing. Without lockdown, they would've passed it to 12-20 people in a week's time with work/supermarket/random events, 12-30 that would've infected more people and, one day or the other, one or multiple would've shown distressing symptoms.
Lockdown prevents that. So that even if half the town gets tested (very good numbers that would be^^), if the two who had Covid didn't, at least they got over it without spread, and thus nobody knows it was even a risk.
The problem with working solutions is that they work, so nobody can witness the horrors of not implementing these solutions (remember Iran and Spain? pilling corpses in stadium after a few weeks). I feel more sane locked inside than losing my closed ones by the truck-load.
On the other hand, at least it is a virus that is easily fought off. 5% danger-rate is nothing compared to what other viruses do. Now is the time to learn and to put state-wide and world-wide systems to avoid a real dangerous one in the future. Not like people will listen... When human bored, human wants to talked about something else. And we are all very bored of Covid really. :p