Instead of seeing Ranboo talking to himself as him having two parts ('ran' and 'boo') or him monologing. I see it as Ranboo going between pessimistic and optimistic thoughts in a state of panic.
He never stays on task, quickly going from one train of thought to the other and is either comforting himself or realizing things that seem to make him spiral.
As for dream's voice, his subconscious is doing some matrix shit

















