Harry Potter: The Biggest Mistake Each Wizarding World Film Has Made
5. Harry Potter And The Order Of The Phoenix: The Poor Editing

This is the first film in the series which was fairly lackluster in quality (for me anyway). It does have a strong finale and the adult cast, especially Ralph Fiennes and Imelda Staunton (playing a character so skin-crawlingly horrible she'll leave you shaking your fist at the screen), are as brilliant as ever, but unfortunately the film as a whole is just a bit... boring.
It's not even bad, it's just mediocre and feels like a painfully standard product. In terms the main thing that holds it back, it's arguably the editing.
For some reason, the longest Harry Potter book was turned into one of the shortest films in the franchise and the film is pretty rushed as a result. It contains far too many montages and speeds through quite a few important things, most notably Harry and Cho Chang's romance. This gives the film a rather detached and flat feel on the whole..
So yes, The Order of the Phoenix was the worst HP film to date when it came out. Still, it was de-throned only two years later...