In the 50 years since the United States withdrew from Vietnam, the number of air strikes against civilian aircraft has dropped dramatically. Once you break down the types of conflicts the United States has had, it begins to make sense why air combat was not common. Even when, it seems, the number of wars happening at any time does not seem to decrease. In World War II, the Korean War, and the Vietnam War, the United States and its allies were fighting the world’s air powers (ie, Imperial Japan, Nazi Germany, North Korea, and North Vietnam). With the exception of Desert Storm, recent conflicts have involved non-state actors (ISIS or Al-Qaeda) or small groups without air power (US Invasion of Panama). In addition, the introduction of drones (or Chinese balloons that check) in the modern battlefield has reduced combat of any kind.
The United States has the most advanced jets in the world today, and only a few of those jets have ever seen combat of any kind. However, on the rare occasions in recent history when a US pilot has had to fire his weapons in anger, they have often been successful.