PCR testing has existed for years, but the specific PCR test kit for SARS-CoV-2 wasn’t (and couldn’t have been) developed until SARS-CoV-2’s genome was sequenced, early in the pandemic. This is why there was a global shortage at the beginning of the pandemic, which China suffered from too.
China was caught unawares by covid; that’s why it ripped through Wuhan, which then had to be locked down. Local authorities had tried to suppress doctors’ reports of the new illness, until the national government became aware and ordered them to reverse that policy. Immediately following the Chinese New Year celebrations when many residents travel long distances to visit relatives all across China, the central Chinese government imposed lockdowns in multiple cities and travel restrictions across multiple entire provinces – 750 million people were under travel restrictions, fully 10% of everyone in the world!
I give no credence to this idea that China let covid spread before the Wuhan outbreak and covered it up. There is some evidence that some Wuhan Institute of Virology lab staff may have been hospitalised and isolated two or three months earlier, but if it was SARS-CoV-2 it must have been contained or nearly so. When China did lock down and impose travel restrictions, it was impossible to hide; nitrous oxide pollution from traffic and soot emissions from coal power stations dropped so much that it was noted by satellites. And the current extremely low levels of covid-19 could not have been achieved, not unless there had been a far more widespread lockdown as stringent as Wuhan’s, and if that had happened we couldn’t have missed it because Chinese manufacturing would have suddenly ceased, like it did at the start of 2020.
This looks like just the usual political China-bashing.