Taiwan has only been a part of China for 216 of the 3,000 years of Chinese history. The Ming Chinese didn't annex it until after the Dutch had opened up the Island. They then lost it to the Japanese in 1895.
Two atom bombs restored it to China only for it to be used as a refuge for the defeated Chinese Nationalists.
Nobody in Taiwan under seventy years has an historical link to mainland China so it Beijing takes over it is going to be a whole load of trouble.