Jimi Hendrix would sound like Jimi Hendrix on your old crappy guitar.

Fact.
Many artists are going from producers to producers because they ‘can’t get their sound’
I hear this so often, and I’m not sure who’s fault it is. 
Granted some producers rush into shaping a track into what they want for it or what they know how to do, instead of listening to what the artist WANT. 
But from my experience, every single great artist / singer I worked with already had their sound just by the fact of showing up in front of a mic. 

Because their sound is in their vocals delivery, in the timing of it, in the songwriting.

The power of a record lies in the emotional power of the artist.

Period.
I suspect some artists expect producers to bring their good song to a song as great as their idols’ songs.
Fair enough, if you don’t augment a song, you’re not doing a good job as a producer but the responsibility has to be shared.  And the bottom line is that there is no secret ‘production tricks’ to make something average amazing.
Like Jimi Hendrix would sound great on your little brothers’ guitar, a great artist sound great on an iphone recording!

The producer’s job is to enhance and maximize all this talent…the results, when the alchemy is here, then can be amazing!!