This is assuming that China's rapidly evolving navy cannot do anything about these blockades. They have massive shipbuilding capacity and currently the most advanced destroyer (type 055) in the world.
> They have massive shipbuilding capacity and currently the most advanced destroyer
The vast majority of their navy and ship building capacity is coastal. Their blue water navy is still minuscule and the challenge isn’t just manufacturing but experienced personnel which is decidedly harder to quickly scale up and is not aided by their terminal demographics.