Because most of the rest of the world has decided to allow the virus to spread, China will eventually have to allow it to spread. However, China has bought two years of time to develop and deploy vaccines and antivirals. That's been immensely valuable, both in lives saved (about 4 million Chinese people would have died if China had followed the same strategy as the US) and in economic growth (China has outperformed most of the world economically during the pandemic).
In this Omicron phase, however, health outcomes from infection have been mild, and most susceptible individuals have had the opportunity to vaccinate. The extreme transmissibility of this evolution has resulted in its general circulation globally.
Therefore, "Zero Covid" is not a sustainable strategy moving forward - its health benefit has decreased, while its societal costs have increased as viral containment has gotten more difficult. There's also no winning condition in sight for this strategy - it'll need to remain in place in perpetuity to be effective.
Taiwan, the best country I've seen handle COVID globally, understood this shift and has gradually loosened restrictions as Omicron has found a foothold on the island. From my perspective, it's a result of medical and public health professionals making decisions, instead of politicians.
In the US, Omicron has killed about as many people as Delta did. It's slightly less lethal on a per-case basis, but much more infectious, so on a population level, it's just as deadly.
In Hong Kong alone, nearly ten thousand people died from Omicron when the government gave up the zero-CoVID policy.
> There's also no winning condition in sight for this strategy
Chinese public health officials have set out very clear and reasonable conditions for easing controls: a high level of vaccination, availability of antiviral drugs, overall mortality less than flu.
It's hard to see China reaching its goal of becoming a world leader if its people must remain cloistered indefinitely.