Taiwan is already an independent nation by all measures that anyone really cares about; the status quo is to their advantage. If China wants to change this, they are going to have to wage war by sending ships across the strait.

Maybe the Taiwanese can defend their nation mostly by themselves; amphibious assault is not easy, even for major world powers. Even more difficult with satellites watching your (extensive) preparations. Even more difficult with hostile submarines prowling the seas. The PLA can't march to Taiwan.