In Taiwan anyone entering must have an app and be traced for location tracking. Everyone can get a sim card at the airport on arrival and you must have a contact traceable smart phone or you do not get out of the airport.
Taiwan is a country that has controlled the virus. China already admitted it lied about the numbers of people who contracted the virus in Wuhan alone by half a million people so how do you think it is in the rest of China?
Outbreaks are still occurring in China and some provinces or cities have been put into complete lockdowns.