Why is speech here a monologue rather than silioquy?

In a play, a monologue refers to a speech delivered by a single character to an audience or to another character onstage, while a soliloquy is a more intimate speech delivered by a character to themselves. In the given context, the speech is referred to as a soliloquy because Macbeth makes it alone on the stage, expressing his inner thoughts and emotions. He is speaking to himself and not addressing any other character or the audience. Soliloquies allow the audience to gain insight into the character's thoughts, feelings, and conflicts, which serves to advance the plot and character development.