In the US, about 70% got two doses of vaccines. That is why they cannot contain covid. In China, they could have done much better with over 90% vaccinations with mRNA vaccines. All these repeated testing and strange lockdowns is not going to increase anti-bodies. You need more vaccine boosters.
University of Hong Kong has research showing 2 doses of mRNA vaccines are more effective than 3 doses of Sinovac.
Sinovac is still effective, but you need more boosters.
University of HK also shows that 3 doses of Sinovac offer the same protection as 3 doses of mRNa vaccines. After 3 doses, all types of covid vaccines offer the same protection. What is the point of using mRNA when it didn't offer better protection. Any additional dose after 3 doses only offer 2-3 months of extra protection. No nation is going to make their citizens taking vaccine every 3 months. It isn't doable and could even cause immune crisis.
So any vaccine boosters are only useful for the first big wave to lower hospitalizations and deaths. After the first big wave, any additional boosters are just offered very limited benefits for a very small percentage of people.
Testings and lockdown lower the spread of covid so the health care system won't collapse. HK, Japan, and Taiwan health system collapsed during their first big wave even with high vaccination rate. HK had 8 thousands deaths which means China would have 1.6 millions deaths if its health care system collapsed like HK did.
Your prejudice is blinded you from seeing reasons why testings and lockdowns are important even if China decided to reopen. It would take at least 6-9 months and 2 big waves of covid for any country to get some breaks from covid. Mostly due to the fact that the most vulnerable have died and remains have been both vaccinated and some sort of natural immunity.