Father Dwight again challenges reason:
The priest’s robes are a ceremonial vesture—a uniform of their sacred office. They are meant to effectively obliterate the priest’s personality. They are also, by the way, meant to be unobtrusive. They should not be creative or clever or call attention to the smart vestment designer or the wonderful seamstress. They are simply to dignify the office of the priest and dignify and beautify the celebration of Mass.
If the Mass is the Royal Marriage Feast of the Lamb, then the priest should dress up for his entrance into the royal court. The robes should therefore be regal in their dignity, their simplicity and their style. As much as possible their beauty should be shown, not by cleverness of design or ornamentation, but through quality materials and fine workmanship.
Why should the priest dress like a king? Because he reminds the whole people of God that they serve Christ the King, and the priest is in persona Christi. Furthermore, they remind the people of God that they too are a chosen people, and a royal priesthood. The priest focuses in his own person and ministry the royal priesthood of the people of God.
The question is why priests still dress in a medieval manner when the church has opened the windows to and come alongside the modern world. Not even Queen Elizabeth dresses like a priest.