Lockdowns happened to slow down the spread of the virus, to buy time to better understand the virus and to try to avoid health services from getting overloaded. I don't think any country ever expected to eradicate the virus by locking down.
Some countries didn't feel the need to lockdown and in many cases have no greater or less infection/death rates than those that locked down tight.
It's too early really to summarise, but the evidence is pointing towards a lockdown being unnecessary in many instances, with the conclusion being reached that "new-normal" measures would have had much the same effect and allowed economies to limp on, no grind to a halt. But things could have easily gone the other way.