Here's something you do unconsciously...
You get stuck in a default rate of speech.
You get stuck in a default volume.
You get stuck in a default pitch.
You see the pattern?
When you get stuck in a default anything, it becomes non-functional.
Why?
Because when people can predict in their brain what comes next, whether it's what you say, or how you sound, they subconsciously switch off.
So the goal if you want people to listen to you and be more engaged, you have to learn how to speak with vocal variety. It's okay to speak fast sometimes because it shows passion, but if you stay there, it makes people anxious. Learn to vary your vocal foundations!