I believe that there’s more than just repetition that makes a pop song go viral. For instance, in this Gangnam Style example, I remember when I first heard it back in 2012, what attracted me at first was the hysterical music video that accompanied the song. And especially for that “hand horse” dance moves. This is another reason why this song was such a hit because people won’t be able to picture those dance moves solely based on imagination and pure listening. That video provided a scenery in our heads, and in combination with that utterly brainwashing chorus, it was destined to be a “masterpiece”. In my case, if it wasn’t for the music video that allured my initial attention and intrigued me to listen further, I certainly wouldn’t have even listened past the first couple of lines, let alone the chorus. Apart from the song itself, there was also a surge of popularity and fever for K-Pops and K-Dramas during those years, which in my opinion, also played a huge role in pushing this song to its prominence. With that said, to answer the original question, yes, I do get listening fatigue if I am only listening to this repeating chorus.
Here’s another example. What is the first image that pops up in your head? Perhaps spatial void?
Now, listen to the same piece with a parody “post-production” and clever use of “music videos” that went viral on TikTok. So my point is that, yes, brainwashing repetition is one factor for viral pop songs, but what’s more important is the “secondary” creativities from others.
Clover's Tree Hollow 