They dont have any athletic markings or tacky branding

The Dress: Baby-Doll The Shoes: The Classic Ankle-Wrap The Dress: Backless Midi The Shoes: Block-Heel Wrap Sandals The Dress: Loungeworthy Maxi The Shoes: Textured Heels The Dress: Puff-Sleeve Midi The Shoes: Leather-Strapped Sandals The Dress: Floral-Print Bustier The Shoes: Toe-Ring Heels The Dress: Ribbed Tank The Shoes: White Sneakers The Dress: Colorful Slip The Shoes: White Mules The Dress: Shirtdress The Shoes: Birkenstocks The Dress: Milkmaid Mini The Shoes: Platform Flip-Flops The Dress: Animal-Print Maxi The Shoes: Square-Toe Heels The Dress: Denim Mini The Shoes: Knee-High Boots The Dress: Sleek Midi The Shoes: Textured Mules The Dress: Tiered Mini The Shoes: The New Espadrilles The Dress: Knit Maxi The Shoes: Block-Heel Sandals The Dress: Utility Chic The Shoes: Flat Lace-Up Sandals Next up, My Job Is to Write About TrendsHere Are the 5 I'm Actually Running Around In This post was published at an earlier date and has since been updated

George V, Edward VIII, George VI and the Queen all wore the white lace dress, as did Prince Charles, Prince William, and Prince Harry
As to their dress code requirements - the 1st is casual (with 1 dressy night), the 2nd is very casual, the 3rd is formal and 4th is totally a "freestyle" deal
Its just that good
Each of these occasions has its own formality level, its own dress code expectation, and its own visual context