"Shanghai seems to be in the last stages of its fight against the worst Covid-19 outbreak in China, which saw hundreds of thousands of cases and over 560 deaths since March."
No. Look, I sincerely wish Shanghai and even the CCP the best with this, but there's a misunderstanding here that goes back to the "R0" debates of 2020. The challenge isn't to get case numbers down (unless you can keep them at 0, which Shanghai is too interconnected to the rest of China/the world to do). The real challenge is to get R, the "effective reproduction number", below 1: ie, achieve a situation where each person infected is infecting, on average, < 1 other person.
How do you get R < 1? One of two ways: immunity (a large % of the population either vaccinated or recently infected), or behavior change - which for omicron pretty much requires lockdown.
https://www.mizzima.com/article/chinese-police-crack-down-beijing-lockdown-rumours
If Shanghai reopens, their now-small number of cases will just grow again until they have to lock down again. I hope they prove me wrong, but that's how I understand it.
The only exit strategy here that doesn't involve a major spike in deaths (which the CCP and indeed the Chinese people are understandably keen to avoid) is mass vaccination, which apparently they are making headway on: "officials are racing to incentivise more retirees to get shots in recent weeks. Around 82 percent of people aged 60 and older have now had two jabs"
But until those vax rates are high enough to either prevent spread or (more plausibly) allow spread with a bearable toll of casualties, Shanghai (and Beijing) will have little choice but to keep locking down.