Two immediate observations. Firstly, China did not fail because it implemented a lockdown.
They failed because they did not use the time bought by the lockdown to successfully build up protection – by vaccination, by strengthening the public health system, and by implementing comprehensive care.
Secondly, looking back at the late 2019 and early 2020 phases of the outbreak: Despite all the failures, China is currently in a better position than it was then.
So, the scale of the current outbreak – 37 million people becoming infected every day and increasing – demonstrates what could have happened in 2020.