Without World War I, there would have been no Bolshevik Revolution, no rise of Mussolini, Stalin, or Hitler. No genocides of the Armenians, Ukrainians, or Jews, hence, no Israel or Mideast wars. No Cold War, hence no proxy wars between the Soviets and Americans. No support for Mao with his tens of millions of victims. No Korean or Vietnam or Central American Wars. No Cambodian genocide. No American Empire.
But if World War I were not avoided, the next best thing would have been a stalemate, with no clear winners. Even a limited victory for the Kaiser would have been preferable to what happened -- Germany's total defeat, its economic destruction via the Versailles Treaty, and the chain of events that followed.
Mike Konrad now has an excellent article in The American Thinker (November 18, 2017), arguing against America's entry in World War I, while unearthing some interesting historical factoids in support of his claim.
You can read Konrad's article here.