Thanks for this reply. I'm guessing the first two points are the most important? And I would have hoped that after 2 years of planning, China could have figured out a lot of ways to improve 1. They certainly have some workforces who have been obligated to live at their workplace, with regular testing.

For 3-5, even if "lock down for 3 weeks" can't literally stop all cases, it still sounds like it could have been achievable to bring them back down to the level where track-and-trace could be effective, and China's efforts would be much more successful than they have been.