HOWEVER,
We don’t live in a world without prejudice and with full equality. We live in a world that has, for many years, been built off stolen labour and the dismissal, and outright erasure, of minority groups.
That is why casting Black actors in "white" roles is fine, whereas the reverse isn’t—because there are far fewer "Black" roles and far fewer "Black" opportunities, whereas "white" is most people’s "normal." When you think of a fictional character in a movie and not an anime/game, most people think of a white male. So putting more white people in, when it should be a Black, or Latin, or Filipino, or Gay, or Trans, or any other character, is just taking away an already limited option from an already marginalised group of people.
What you're saying is stupid on both sides, is really just the difference between Equality and Equity.