First, a "half dozen cities" is nothing in China. Currently, the largest city under lockdown is an out-of-the-way city near the border with Vietnam that almost nobody outside of China has even heard of (I'd wager most people in China aren't even familiar with the city): Baise (百色市). All the major cities are open.

Secondly, if you follow the different outbreaks in detail, you see that the Omicron outbreaks are not just being slowed, but completely extinguished. The outbreaks in Tianjin and Beijing look like they're over.

There will continue to be small, isolated outbreaks that occur when the virus slips through the border quarantine measures. However, China has showed that it is perfectly capable of extinguishing these small outbreaks one-by-one.