I'm not going to defend any specific action especially when taken in isolation but in the large US global hegemony has been massively beneficient.
Like throwing people in the sea, torturing civians by thousands, bombing presidential palace. The world was becoming a safer place, even on the wrong side of Iron Curtain, but this Chile thing was really a step backward. The guy was caught in UK and held behind bars for the rest of his life for a reason.
Nope, I don't understand. What's the use of liberty and democracy when you end up worse than commies?
Not everything the USA has done has been selfless and not everything has worked out for the best, maybe not even the majority! But I must challenge the original assertion: when you take into account both capacity and intent, America was by far the most beneficient power of the 20th Century.
But other than those specific local actions, taken in isolation, it's all been massively good and massively beneficial.