Ope Ope has a proper build-up, and it has always been Yonko tier fruit. Law is fighting, like, basic GGnM attacks with one of the best moves he could muster. So it's bye bye Law once BB starts using his own big guns. Meanwhile, Luffy is given a Yonko++ fruit outta nowhere when we're told for like 1000 chapters that it's a third-tier fruit. Both are not the same.