There's no refuting the fact that Vaughan has not achieved the highs so many predicted back when he emerged in the mid-1990s. It's always been the same. David Byas, speaking to Nasser Hussain in 1999, said it best. "He always looks good. But he always gets out".
However, like so many, the career average just doesn't tell any story of note. There's Bangladesh (and Zimbabwe, though he batted just twice against them), there's the opener\middle-order split, there's the incredibly lucky year of 2002, there's other things besides - most notably that he was never all that far from changing position, sometimes through his own choice.
Vaughan's career is a deeply complex one, just like most others.