what if you got a white dude that was raised by a black family in a black neighbourhood arguing against a black guy raised in norway by people whiter than snow on black culture? sure, you can argue that the white guy has never experienced being black, but it's amazing what you can learn from other people. or a man who has three sisters, a mother and a wife all very open about anything regarding being female and happens to be a gynecologist bo boot arguing with a 20 year old woman who has never even had a look between her legs on female anatomy? those are extreme examples but the point is that while being a member of a group does not necerrerily mean that you know more about it than an outsider just because he is an outsider.

"I know about black culture because I am black" is a valid argument (but imo not sufficient on it's own)

"you aren't black, you have no idea what you are talking about" is not valid.

if you meet someone who pretends to know more about your kind than you do, beat them with actual data on your kind. not with a "stfu outsider". that's how you break up inclusive groups and polarize people.