Taiwan's identity is complicated, the vast majority of the populace are some variant of what we consider Chinese (either Hakka, Fujian/Hoklo, or "Mainlanders" who are those who emigrated from elsewhere in China, and particularly those who immigrated after the loss of the KMT in the civil war) but that masks the enormous divide between the first two groups and the latter group (and of course including the aboriginal groups, who while small demographically are important especially in political narratives) thanks to how the KMT governed post 1949, in which mainlanders basically had a monopoly on politics and all major socioeconomic positions and heavily pushed the notion that Taiwan was just another part of China.
The anti-KMT politicos in response really spawned the modern notion of Taiwanese identity as an almost Americanesque melting pot culture, and pushed to highlight its uniqueness and differences from mainland China. Since the 1990s this unique sense of Taiwanese identity has really took off and absolutely dominated in the past few years as the CCP has fallen back into heavy handed authoritarianism. The Hong Kong response was a disaster for China in the long term identity debate in Taiwan in my opinion.
If China manages to successfully take it over, it would remain to be seen if they can successfully suppress the Taiwanese who would resist them. In all probability it will be, like I said, their Vietnam moment. A mini-Syria, if you will.