It's pretty trivial to prove that thinking is faster than speaking -- just read a 200+ word article out loud vs. "in your head" and the difference is clear. The gap in speed will become larger as the overhead behind speaking grows.

The real question is: does it matter? All around me I see people interrupting each other and failing to comprehend what each other is really trying to say due to impatience. Neuralink is interesting, but would probably exacerbate that particular problem.