Firstly, there is only a question of 'unify or declare independence' because of continuous pressure from the US Empire for the last half century. Continuing the status quo benefits all parties because the RoC's largest trading partner is the PRC (obviously, because it's a country of 1.8 billion people that is literally right offshore) and gradually increasing integration was the obvious natural course.

Until the US, which still maintains an official One-China policy, decided it needed another way to attack China. But maybe, China really might just smash its way in by force... any day now!

If events had unfolded based on normal political and economic trends, Taipei would probably have ended up as an autonomous province under the PRC, similar to Hong Kong or Macau, because the Chinese central government is comparatively hands-off and local governments are mostly allowed to do their own thing - a policy started under Mao called (I love Chinese policy names) Let One Hundred Flowers Bloom, Let One Hundred Schools of Thought Contend.

Oh, but of course you thought the entire Chinese population was controlled directly by Xi Jinping like units in an RTS, didn't you? Because you're a know-nothing racist fuckwit - or not, after all, it's okay to say that asian people are yellow-skinned and beady-eyed if they're enemies of the US! Xi is going to finish his third term, see out the opening stages of the Belt and Road Initiative, then retire like every other Chinese President and foreigners with full bellies and too much time on their hands will cope and seethe that the next one is also a horrible dictator (until that one retires too).