The word arrogance means to turn away from questioning. I understand it has its roots in the Latin words ab, meaning away, and rogare, meaning to question.
Best practice is arrogance in motion. The minute you believe you have achieved best practice, you stop asking questions. Well of course you do, what you have is the best. Best practice see, it says so.
Good practice and better practice are both useful places on an improvement or development journey. But best practice?
Best practice is game over. You lose, they win.