The Taiwan question is a mixed development and ideological one.
Looking at development, first tier mainland cities are already par or slightly better than Taiwan in terms of raw economic output per capita. In 10 years probably rich provinces like Zhejiang and Jiangsu will be par or better than Taiwan on the same metric.
However, mainland society is rife with anti-social behavior, as a result of crony capitalism from 1990s to 2012-ish. Although not quite at the level as gangraping Dalits and stringing them up on trees, it is still really bad in many respects especially traffic. The upper class and upper middle class are mostly arrogant and money grubbing scum. Only the more disciplined among civil servants and party members (including central government level) hold everything together.
Taiwan's massive advantage in terms of social harmony is a "force multiplier" that propels its current development level to well beyond that of mainland first tier cities. Taiwanese have picked up some of the better parts of Japanese culture.
On this topic,
this article is highly recommended.
In terms of the ideological issue, it's just a historical problem. Pro-US and pro-Japan views are the majority because there is little personal risk to being anti-China. The moment they are physically threatened, they will switch sides quickly. The solution here is simply to spill some blood.
In conclusion, mainland needs at least 10+ years to improve its society to the point where you don't have arrogant and money grubbing scum dominating the private sector positions of power. Once that finally happens then spill a bit of blood in Taiwan and everything falls into place.
Xi Jinping made it a priority starting from a few years ago. HK is undergoing a deep level retooling to integrate it into the surrounding parts of the mainland called the Greater Bay Area. See below.
https://m.scmp.com/comment/insight-...eater-bay-area-chance-hong-kong-show-it-hasnt