Those fortifications are a mixed bag in my opinion. On one hand, they help create area denial for the South China Sea. On the other hand, they are vulnerable

Those fortifications are a mixed bag in my opinion. On one hand, they help create area denial for the South China Sea. On the other hand, they are vulnerable and difficult to defend. Probably also a lower stakes target. If the Chinese shot at a foreign plane or ship, I think it would be tempting to attack one of these outposts. Easier and less inflammatory than attacking a mainland air base or port.