Why is a good cover artwork even necessary?

There are almost 40,000 songs released on platforms such as Spotify every single day.
A good cover artwork helps you to stand out in this huge marketplace and attract new fans!

What makes a good cover artwork?

There are two key things that make an artwork good:
The visual impact on a listener and the emotional representation of the song.

What kind of feeling does the artwork communicate to the listener and how does it represent the emotions that the song is trying to deliver?

were used to create these artworks