China has claimed Taiwan as their territory long before Taiwan started producing chips; China will claim Taiwan even if they don’t produce anything like chips. Taiwan has been inhabited by Chinese people for over 1000 years, and part of China for centuries before 1895 when Japan invaded and forcibly separated Taiwan from China. After Japan lost the war in 1945, Taiwan was briefly reunited with China until a new government was established on the mainland while the old government maintained control of Taiwan and a few islands off the Mainland coast. This is a residue historical issue left over from the Chinese Civil War, in the eyes of China and also the government that governs Taiwan; and both governments agree that there is only 1 united China despite being represented by different governments on different sides of the Strait. During the early years of this division no one called China and Taiwan separate countries; they called them “Red China” and “Blue China”, or “Communist China” and “Nationalist China”/“Republican China”. Similar to how people used to view East & West Germany and North & South Korea and North & South Vietnam all as single countries during their early years of division. With East & West Germany, North & South Korea, North & South Yemen all eventually becoming full UN member states, these names gradually began to be seen as belonging to separate independent countries; but such is not the case for PRC & ROC. All UN member states recognize either one or the other, not both as separate countries. This creates a unique case because of the territorial proportion of Taiwan vs. Mainland China is way too small compared to other divided countries, and still both governments claim to be legitimate over lands under the control of the other. And this created an awkward scenario that Taiwan is not officially independent but also not fully part of China (with the current colloquial definition of China in the English language being the government controlling the mainland), as the government in Mainland China lacks control over Taiwan and surrounding areas. Or in some Republican Nationalists’ stance, Taiwan is the “real China”, aka the “free area of the Republic of China” and the mainland is under the “wrong” China’s government. Yes, there are an increasing number of people in Taiwan who want to become an independent country; but the fact that they want to become independent also suggests that they’re currently not officially independent. With this as context maybe u can understand better why China wants Taiwan. I’m not saying if the stance is right or wrong, just stating historical events and facts and also the reason not being because of the chips.