1) this is the opposite of elegant. Something that can be expressed in a few clean lines of html + css turned into a wall of barely readable JS, where you have to jump between functions just to find the correct place in the DOM tree.
2) why do you call it "declarative"? This is procedural. React or Vue is more declarative (you declare the state, and it renders based on the state).
1. You see a "wall of barely readable JS" somewhere? Eye of the beholder, I suppose.. ?
2. Perhaps "reactive" would have been a better term. In fact, I'll change it. To me, the difference with procedural is that functions automatically rerun when the data they access changes.