A great producer is going to analyze you and learn your strengths & weaknesses. He will know how to use them to your advantage. He (or she) will push you farther than you thought you could go.
I’ve done this several times—artists thought I was just being an asshole, but they later thanked me for pulling the extra mile out of them.
The compound effect of this is that the artist now has an expanded worldview of their skillsets.
They can now be farther along the path for the next session, where the producer will push them even FURTHER.
It’s a positive feedback loop that skyrockets growth.
Get a good producer who you trust (and trusts you).