In the Astronomy Picture of the Day from August 8, 2020 ("[Crescent Saturn](https://apod.nasa.gov/apod/ap200808.html)"), the caption states

> 
> From Earth, Saturn never shows a crescent phase
> 
> 
> 

Why is this? We can observe phases on planets such as Venus which have an apparent size a lot smaller than Saturn. Saturn is not tidally locked to the sun ([only Mercury is](https://en.wikipedia.org/wiki/Tidal_locking#List_of_known_tidally_locked_bodies)).

So why does the sunlit face of Saturn always face Earth?