I think the being unable to understand anything he said gag was from an early rumor (maybe based in reality) that one of the reasons the standalone Gambit movie didn’t move forward was that Channing Tatum couldn’t pull off the accent. So in Deadpool they hammed up the unintelligibility and inconsistency of the accent on purpose to have the joke of “Who is your dialect coach?”

You wouldn’t see any billionaires.