The UN Charter, article 4, states that “Membership in the United Nations is open to all other [non-founding] peace-loving states which accept the obligations contained in the present Charter and, in the judgment of the Organization, are able and willing to carry out these obligations.” Taiwan is indisputably a “peace-loving” state — in marked contrast to China, which not only makes threats against Taiwan, but supplies arms and financial support to warlords, dictators, and genocidaires around the world, including in Sudan.
Such is the hypocrisy of the UN. China, a communist, oppressive, state is granted preference while a small democratic, peaceful state is shut out. I’m not sure if it would matter much if Taiwan was granted a seat in the UN. It’s far too weak and passive to do anything to benefit or protect Taiwan from China, who not-so-secretly wants to bring it under it’s rule.