You have to take a look at a map to really understand Taiwan's importance.

Taiwan isn't about military proximity. It's about access shipping access. Try open up a map. Despite China having a vast coastline, they do not have access to the open seas. Every one of their shipping lanes requires passage through another nation's waters.

If a heavy conflict were to erupt, China's supply chains would be cut off via naval blockade. It's a huge risk to China, and one they've attempted to ameliorate via the Belt and Road Initiative.

That changes if they acquire Taiwan. Taiwan's importance is not of offensive, but defensive primacy.

> If a heavy conflict were to erupt, China's supply chains would be cut off via naval blockade

Or possibly the 30+ fast attack submarines sinking every military or resupply vessel in the region, augmented by a colossal amount of rapidly-deployed naval mines.

Taiwan doesn't buy them much in this regard. Why would China be permitted to use sea freight at all in a "heavy conflict" scenario? Why not just sink these vessels near their origin - why allow Brazilian soybeans to even make it out of the hemisphere?

> Despite China having a vast coastline, they do not have access to the open seas.

I didn’t realize that Okinawa is halfway between the Japanese mainland and Taiwan, and the Japanese territorial waters extend right up to the Taiwanese EEZ on account of Japan’s far-flung southern islands.