Well, yeah (quoting The National Interest):
China’s military buildup is about Taiwan, not the South China Sea. According to reports from the Pentagon and Office of Naval Intelligence, conquering Taiwan is the core mission that drives the People’s Liberation Army (PLA). Why? Because China’s authoritarian leadership is deeply insecure. Beijing views the Republic of China (ROC, or Taiwan), which exists as an independent and sovereign state, to be a grave threat to the communist party’s vice grip on power. Taiwan is dangerous because it serves as a beacon of freedom for Chinese speaking people everywhere.
The theme of China preparing to invade Taiwan has long been a recurring theme of this blog.
And building up forces in the South China Sea isn't just a distraction from the true objective. It covers China's southern flank for the invasion.
And really, even if China is just putting their forces into a kill sack down there, if we focus on that while China invades Taiwan, isn't that a good trade for China to make?
Remember, this isn't a local question: the repercussions of China taking Taiwan are great.