I don’t think this is true. Plenty of music videos, including incredibly popular ones, are essentially short films that use the song as a soundtrack.
The elevation of performer and performance over composer and composition reached its peak with jazz, which coincided with the technology of recording, when individual performances could be preserved in the same way sheet music allowed compositions to be preserved. Pop is different - it’s about the merging of the performer and composer into a unitary being, the singer-songwriter. Pop strives to maintain this illusion even when it’s patently false (cf. Dr Luke et al).