That brings me back to what I said initially. It's not a legal fiction. The Republic of China has existed since 1911 and took refuge in Taiwan. Taiwan is a geographical name, and the Republic of China still exists. Taiwan's president, Tsai Ing‑wen, is fully aware that, if she decided to change the country's name tomorrow, it would spark nothing short of a war. The National People's Congress of the People's Republic of China passed a law clearly stating that, if the name is changed, it would be war. That is crystal clear, set out in no uncertain terms. Obviously, Taiwan's government would not dare do such a thing.
Naturally, Taiwan has hard-core sovereignists, but they really are a minority of the population. They would like to see the country's name changed to the Republic of Taiwan to reflect the reality, but short of a revolution in mainland China, it won't happen in our lifetime.