Ehhhhh. There’s a middle-ground on the cleanliness of chef’s whites. I’ll agree that there are some chefs who could be mighty messy and still cook well. But in a nice restaurant (that actually has a chef, and whites), nice whites are often a sign of pride and care. Compare Gordon Ramsey, or even some of the winners, to the other contestants. This isn’t a hard and fast, 100% rule, but often you get dirty because you don’t care, don’t pay attention, or otherwise can’t handle being attentive to yourself and appearance alongside what you’re doing in the moment. Not (often) qualities of a good chef. Also, nice whites = the management/front end cares, gets them laundered well and often, and probably keeps an appropriate amount of replacements available. It’s is a legitimate indicator.