China's drills around Taiwan are necessary to both prepare the Chinese military for a possible military engagement initiated by the US and push forward the reunification process. China has every right to assert itself over its own sovereign territory, and the US is playing with fire by flagrantly disregarding its previous historic agreements with China.
China is clearly overreacting to Pelosi's visit. US support for Taiwan has been a cornerstone of US policy in Asia for over 70 years, and it's China who is being provocative by launching its largest ever military drills near the island. The PRC's loud saber rattling is menacingly close to Taiwan, which marks a dangerous escalation.
There is a 25% chance that China will launch a full-scale invasion of Taiwan before 2030, according to the Metaculus prediction community.