This seems like a false narrative you're creating and I don't know why.
Who is legitimately undermining The Dark Knight's box office run? It's not an insult to say it wasn't a phenomenon overseas. It was only the 2nd biggest movie internationally of 2008. Was Indiana Jones and the Kingdom of the Crystal Skull a phenomenon? The Dark Knight barely made more money overseas than Mamma Mia!, Kung Fu Panda, Madagascar: Escape 2 Africa, Hancock, and Quantum of Solace. Were they phenomenons?
It had a great number, but not some once in a lifetime achievement. Nothing to be puffing your chest about. The domestic run though? Legendary.