Because countries in Asia did manage to arrest the outbreak, so that was the standard from then on once we knew it was possible.
Add to this an existing culture of using face masks and gloves in public (i.e. supplies of those things were already in place), and you've got a very different scenario compared to most of Europe for example.
This is a big one. Around these parts wearing a mask means people assume you're sick or immunocompromised.
Hard to make the argument that testing is of primary importance considering Japan did almost none and still didn't see a significant outbreak.
Obviously Sweden couldn’t scale to the same testing as e.g South Korea, but few countries could. Perhaps one lesson would be that if you can’t scale testing then locking down until you can would be good?
Japan did 90%+ mask coverage.