A good camera isn't necessary for a good photo... but it makes it a hell of a lot easier.

For me, upsides of a good camera include:

    * More precise control over photographic characteristics (most important for artistic purposes: depth of field and exposure time)
    * Higher information-theoretic entropy of image (which leads to better perceived photo quality and more flexibility in post-processing)
    * Ability to bypass or customize automation around color science, de-noising, etc. so that you're not stuck with whatever style the device has built in
    * ILCs allow you to select a lens and other optical components that match the artistic goals you have in mind (esp. focal length)