South Korea demonstrated from the beginning on how to deal with this (despite their slow start - which still is super quick compared to most western countries). But its completely wrong to think they passed it. They also have massive impediments at the moment. Back to normal? Far from it.
But people are still working and their economy is still running. This is a HUGE improvement over what we have currently in the USA.
The problem is contact tracing only works when the number of new infections is manageable, though. That's why it's so critical to react early and aggressively. Once it becomes unmanageable, the only solution is mass quarantines until the numbers are manageable again.
The best analogy is a fire. If it's just embers, one person can stomp it out. If you wait for it to become a forest fire, then it requires drastic measures.