China is now seeing a wave of secondary infections as they relax travel restrictions and as people enter the country from elsewhere. They have not stopped the spread, they simply slowed it down.
That's the whole point. If you slow it down you can avoid the rapid spike in severe cases that overwhelm the system. It's like traffic -- once you surpass a certain volume, the system locks up and throughput drops.
I think the point was to do a controlled restart while making sure the rate of secondary infections remains low enough that the impact of the coronavirus remains less than the flu.
