They certainly gave the robe a majestic appearance: but the Torah explains them as a means of announcing the priest’s entry into the sanctuary: “The tinkling of the bells shall signal his approach”.
Rabbinic commentary draws a moral lesson from this practice. Just as a high priest must not burst in to the sanctuary without warning, it is correct practice for anyone to hold back and signal their arrival no matter where it is that they want to enter.
A topical Purim example is the entry of Esther into the king’s throne-room – without announcing her arrival and receiving the king’s permission to come in, she had to remain outside, even though she was his wife.
The Talmud says that Rabbi Akiva told his son Rabbi Yehoshua not to enter even his own house without warning, all the more so the house of his mother (Pes. 112a).
The sages say that one must knock before entering a room or house, even his own: a person’s own home is God’s throne-room – a mikdash me’at, a minor sanctuary, and every Jew is a member of mamlechet kohanim, a kingdom of priests (Ex. 19:6).
It is no answer to quote the command of Achashverosh, that “every man should be the master in his own house” (Esth. 1:22) or to echo “Les Miserables”, with the song, “Master of the House!”
At all times a person should move with humility as well as dignity, with respect for everyone’s privacy including his/her own.