White people are deceptively trying to convince people that black face is purely the act of depicting someone as black and so a non-white depicting as white is equivalent. "white face".
That perspective completely blind spots the true historical meaning behind black face.
Black face is very distinct, and its purpose is to dehumanize blacks. Robert Downey Jr in Tropic Thunder wasn't true black face. Neither was Jimmy Kimmel pretending to be Shaq. There was no dehumanizing acts in their portrayals.
True black face is pure black paint, red lips, oftentimes white paint over the eyes as well. You know "Jim Crow laws"? Those laws were literally named after the first popular black-faced cartoon character, Jim Crow.
Black face is specifically about portraying slave-era Blacks, and Blacks as lesser than the populace being entertained by them.
Now someone tell me exactly how it's even possible to portray "white face" with this historical context in mind.
It's not.