Standing for the Bride?

Why do guests and everyone at your wedding ceremony stands for the Bride? Where did this tradition come from? My future husband wants to be traditional and not see me in my wedding dress or veil until i am walking down the aisle with my dad. I have been to multiple weddings in the past and every time the bride walks down the aisle everyone stands for her, I am traditional in that respect, but I do not like being the center of attention. My fiance said to feel like a princess, it is the one way I can be the center of attention. For those of you newlyweds or brides to be, how do you feel about having everyone stand at your wedding ceremony? I just feel extra nervous because I had breast cancer at 29 years old and my ballgown wedding dress will have a pocket made for the strapless part of my right side since I wear a breast prosthetic and I did not opt for having breast reconstruction surgery. I will be 34 by the time of my October 2024 next year, I love LOVE my wedding dress, but I am worried people will notice the prosthetic.