It is a distrcation. There are so many more important issues to be concerned with than who plays Harriet Tubman in a fictional movie. It was a Black American who played Malolm X. Did that change anything? What about when a Black American played Jackie Robinson? Did that solve police brutality? So my position is that the outrage over a Nigerian actress playing Harriet Tubman in a fictional movie would be better served on more pressing concerns like police violence, gentrification, the failing educational system, or even the fact that black people are dying due to poor housing conditions. If a Black American woman played Harriet Tubman instead it would not change the material condition fo Black Americans.
And much of what you said is misleading. For example, how can you accuse Africans of stealing ADOS culture when ADOS culture is itself rooted in African culture. And the idea that ADOS have been “marginalized” by the diaspora for generations is flat out wrong. You also sound confused. You complain about Black Americans being mariganlized, but then you also complain when people on the African continent express their desire to welcome Black Americans back home. And the fact that Africans are thinking about Black Americans as a motivation for fixing the continent’s problem is the literal the opposite of what you said about Africans being concerned only with themselves. So like I said, you sound confused.