It's just posturing. China has a large but poorly equipped and even more poorly trained military. Also, Taiwan is the premier manufacturer of computer chips, and China is one of their biggest customers. If they damaged Taiwan's chip mfg, China would grind to a halt within a week's time, max.
Due to the pandemic and supply chain issues, there are not enough chips being manufactured as it now stands. Destroying/harming one of the major chip sources would harm China as much or more as it would hurt the US.
China makes a lot of computer chips, but they are lower-level ones. The extremely sophisticated and advanced chips are from Taiwan Semiconductor and its peers. They supply 90% of the global high-end semiconductor chip market.
Xi is just making noise because he's checking to see how much attention the US is paying to Asia, with the Ukraine/Russian war still active. China's economy is in recession and their New Silk Road project is rapidly failing.
BTW, there is another reason why Russia is so intent upon annexing Ukraine, or at least the maximum industrial regions they can hold onto. Ukraine doesn't make chips - but they have the resources needed by chipmakers:
"...The U.S. has historically sourced as much as 90% of required semiconductor neon from Ukraine, which has also provided about 70% of the global supply. Ukraine is also a major supplier of xenon and krypton gases, also critical to chip manufacturing..."
- Sloan Review, M.I.T.