China used some good old communist methods, mobilise the entire population in the fight against the virus. Virtually every apartment building had someone sitting in front of it taking temperature. Every restaurant had. When someone was sick, two others were checking in and ensuring that people comply with regulation and go shopping for them. When China had one case in a city they cordoned off half a million people and tested millions.

South Korea wasn't quite as stringent with lockdowns but it worked the same way, compliance of the population, quick testing and human tracing. Same in Taiwan. What worked there was giving you a phone, locking you in your apartment, having the health department call on you three times per day and fining you 10k bucks if you didn't listen.

The tracing apps did, to put it mildly, jack shit. The solution, which is why a lot of Asian countries, even relatively poor ones like Vietnam, made it out of this, was adherence to law and compliance and harsh measures for those who fell out of line.

Throwing some random Apple dongle at every problem fixes exactly nothing, you can install a hundred apps on your phone, if your entire population has lost the collective will to actually act in coordinated fashion you're in the dog house.