I don't use Amarok, but looking at screenshots, it looks similar to other Qt applications on Windows that seem to sit in this uncanny valley of coming quite close to looking native, but just different enough to feel strange. I also don't use the Spotify app, but it seems from screenshots to do a better job of appearing like a native Windows 10 application to me.
Taking music players for an example, I prefer the way Amarok (Qt) looks compared to something like Amazon Music or Spotify.