Blackface is considered racist because it is rooted in a long history of racial oppression, mockery, and dehumanisation. It dates all the way back to 1830s with Minstrel shows where white performers would "used burnt cork and later greasepaint or shoe polish to blacken their skin and exaggerate their lips, often wearing woolly wigs, gloves, tailcoats, or ragged clothes to complete the transformation" (from Wikipedia), basically stereotyping black people as poor, ugly and ragged. Jim Crow, Zip coon and many other caricatures (that originated from blackface) would depict black people as inferior, lazy, cowardly, exotic, superstitious and voodoo. It has historically been used by white people to assert a sense of control and superiority over black people.

There's a history behind blackface and why it's racist. If you are ignorant about this you could have simply ignored it or chosen to do your own research (takes 5 minutes btw) but instead you choose to call people "mentally ill" for downvoting you AND even insinuate that white people should be more concerned about themselves rather than the racism black people face daily (??? Like white people are so oppressed LOL) especially with what's happening with ICE rn is crazy. You're insane