The way we dress indicates the community we belong to. Some communities value conformity to a common core of values. Conformity in dress is taken as indicative of the broader shared value system.
That said, in today’s day and age, non-conformity to a mode of dress does not mean that one doesn’t have equal or even stronger emunah or avodas hashem. And conforming to the dress code doesn’t mean that you aspire to the broader value system. For adults, this is often a social indicator of belonging to not belonging to the community. For teens who were born and raised in the system, changing from a white shirt to something else can mean a rejection of the community.