I think giving songs and albums their own artwork really helps give them their own identity and visual meaning, if that makes sense. I strive to differentiate all my singles and try to give each them their own "eras" for lack of a better term, but moreso just something to make every one stand out from the rest.
Because I try to give each single its own identity, I've never really given much thought into creating an album or EP, since those act more like a collective of songs that express a singular identity or theme. Millennium was an exception since it was moreso testing the waters, and I do regret releasing it in its unfinished/rushed state. However, I wouldn't rule out ever releasing an album or EP again, I'd just have to be extremely sure that it's something I'd want to put into the world.