A song is IP. A car is not technically IP but merchandise is involved so I’d say that counts. A movie is IP. A game is most certainly IP.
By your opinion, observing that game before making my own “infringes” their IP. And same for the song. And by that test, watching a movie at a friend’s is piracy, and borrowing a friends car is robbing the car manufacturer of profits.
It really seems to fall apart if you simply place a black box over the “who” of creating something completely different, seemingly based solely on our biological memory not being digital.