Why Does China Persist with Its ‘Zero-Covid’ Strategy?

They have a population decline problem. 1 child policy was also anti-female. So they have the cultural revolution boomers retiring and the 15-19 year old group is tiny. Even if they allow down to age 4, they are at a net loss for productivity.

It also comes at a period of time where they haven't quite done enough for the development and may fall short of the threshold.

zero-covid on the otherhand is trying to make sure nobody young dies.

IMHO Xi Jinping is the fundamental reason. Since he took power in 2012 he has continuously shut down freedoms.