I actually think they did improve it though
The demo had way too long transitions into the choruses
It didn't even have a bridge, which is the best part of either version
It didn't have the end part where all the production meshes together
Not to mention some of the lyrics: "Take that **** back to the 80's"
The only (kind-of) plus is the chorus sounding slightly better, but it couldn't have been left as it was