How is that “dehumanizing” when human is literally in the explanation. Had it been “female apeoid” I’d have agreed, but humanoid… So “moid” for male humanoid is “dehumanizing” too?

"A humanoid is a non-human entity with human form or characteristics." https://en.wikipedia.org/wiki/Humanoid

A humanoid is by definition not human, hence calling a human a humanoid is dehumanizing.

-oid is like -esque, in that it describes something that resembles the root word, without actually being it.

And the n-word literally means "black". But from the context we know that it is being used as a derogatory word just like in this case.