On stage, generally speaking, the story is stopped or held back by songs, because that's the convention. Audiences enjoy the song and the singer, that's the point. ↗
One difference between poetry and lyrics is that lyrics sort of fade into the background. They fade on the page and live on the stage when set to music. ↗
The fact is popular art dates. It grows quaint. How many people feel strongly about Gilbert and Sullivan today compared to those who felt strongly in 1890? ↗