The F 15 has a 110 to 0 record in air to air engagements. Many of these battle were with aircraft that were close to or equal in technical capabilities. The reason for this was not technology or numbers, it was the aircraft were operated by Western or Westernized Air Forces. This meant they had the overwhelming advantages in supply chain, maintenance support, training, exercising, and command and control.
China may have lots of ships and planes but they still have a culture that subordinates military competence to political fealty at all levels but crucially among the senior leadership. They can dabble at delusions of regional hegemony, but they will never be a threat to Western Militaries.
The question of Taiwan is an interesting one. I believe the chance of invasion is effectively nil. I think Xi has got to know that it would be a bloody, ugly campaign that would highlight the inadequacies of the PLA. Conversely an invasion of Taiwan would be a very bad indicator for the rest of the world. It would indicate that control by the Communist party was so shaky that a risky military adventure was preferable than dealing with domestic issues. This would be a very bad development and portend a potential very messy and uncontrolled reordering of China's internal power structure. That would not end well......