It seems to me that groups who can signal within-group status unambiguously will tend to downplay fashion.
Examples. Tech/Science smart people don't bother much with it, as it's not possible to fake it in their world, while humanities 'intellectuals' have to play a role, as their intelligence can't be casually observed by outsiders. Ditto for Athletes, or really anyone who gains substantial status from visible muscles or visible grace.
I would expect this to also be the case for people who engage in any sort of formal contests, e.g. poker players.