I think the recent protests are the result of the lockdowns that have been in place to varying degrees over the past two and a half years there. With the billions in population that China has, keeping that many people socially isolated for this long a period has pushed people to the limits in terms of how much solitude they can handle without snapping.
As for recruiting early adolescents to the be the COVID police, it wouldn't surprise me if they were told to do it to boost their social credit scores.