Of course it's not a guarantee, I didn't intend my message to make it seem like it was. I think upward movement has a higher chance than downward movement, though. And considering staying where OP is at is causing issues, I said upward.
I could have said "seek movement until you no longer feel like you're the smartest person in the room", I guess.
What do you mean by "upward"? If it's the classical meaning: you're not guaranteed to find smarter people higher in the organization.