[YorkshireSeason]

Taiwan only holds on to the historical claim to ruling China because a change in status is feared to trigger the China's anti-secession laws, which in turn would lead to an invasion on Taiwan by China. Better not to "rock the boat" at this point.

(Taiwan probably also sees this as a bargaining chip, to be given up at an opportune moment (like the Kinmen Islands), in exchange for something else, e.g. China accepting Taiwan's independence. I suspect this would have been possible at some point when China was weak but seems unlikely now.)