I also read that apparently the show has only black people with super powers because it is “based on real science since people with sickle cell disease are mostly black,” but mostly is different from only. White people can also have SCD, so why couldn’t the show have one who also was born to parents with SCD?

You’re right, the show would have been so much better if they added a token white character to pander to white people. They don’t get represented enough, and them heavy handedly shoving one in would have been perfect.