White people don't think white people have a culture but we do and it's preoccupied with status, hierarchy, and petty interpersonal domination.
Part of what allows white people to maintain their ambiguous sense of superiority over others is that they never imagine it as a culture, they assume status-seeking behavior is universal, even the norm, and that everyone else who isn't seeking status must be failing.
Dismantling white supremacy means deconstructing white supremacy culture and reevaluating our cultural values because the values created to keep white men in positions of power and authority at the expense of others are probably shitty values worth re-examining.