It’s not “Black” that was the problem. It was “the Blacks” and “a Black.” People don’t say “a White” or “a white” to describe a person. That’s why “African-American” came into use.
I had described the maintenance worker I was trying to identify, since I couldn’t remember his name, as “black.” They immediately knew who I was referring to, so the descriptor was apt.
I value efficiency in communication. Seven syllables in “African American” as opposed to one syllable. It’s a no-brainer.