Maybe Xi is more looking to Venezuela than to Ukraine. A full scale war is an option (and a good way to test your weapon systems and armed forces) but it destroys Taiwan and te economy of it, which significantly decreases the value of the conquered country.
What the US did to Venezuela, weaken it by years of sanctions like embargoes and blockades, supporting the opposition, infiltrations, propaganda, bribing corrupt officials and officers, and eventually abducting the leader, takes a lot of patience, but in the end the cost-to-result ratio is much more rewarding than a scenario like Ukraine. And it has also much less negative effect on china's own economy than a full scale invasion.