There are several possibilities that I think are worth exploring.

Germ Freaks This virus may genuinely terrify the ruling class atop the CCP.

It’s a psyop The short term hard lockdowns in Wuhan in early 2020 were falsely advertised as an astonishing scientific success, but were most effective as an information operation to shut down the world, while seeding the idea that lockdowns would help to crush the virus.

National Hubris/Believing their own press Every country modeled their lockdowns, a novel concept that did not exist prior to 2020, after the Wuhan lockdown. This level of admiration may have acted to affirm China’s well-known, baked in superiority complex, and convince the Communist Party that it alone has the technocratic authoritarian capacity to wage a successful war on a virus.

Internal politics There remains tremendous infighting in the ranks of the Communist Party. Shanghai is perceived as one of the more “liberal” cities in China, and the lockdowns may have been motivated by competing political factions desperate to win over influence and power.