Thats literally the only reason why it was good at the time, because it always topped the game before it which are always used as arbitrary reference points.

That said, it was the first huge popularization of open-world games. It was so popular that linear games suffered badly for it. Though that has since changed since people now fondly look at those games and regard them as "set pieces" whose rigid structure was intended to achieve a specific reaction fromt he gamer.