This isn’t about Covid. It’s about economics. Shanghai is a big port city, and China’s leaders are keeping it shut down so that no exports to the Western countries happens, thus screwing up the supply and distribution to the U.S. and EU of goods, harming our economies. It’s China’s way of helping Russia and sticking it to us, as they consider us their enemy.
Wouldn’t be surprised if they shut down other port cities too, allegedly because of Covid as an excuse. China could care less if millions of their own populace starve or die. It’s their way of culling an overly large herd.