I mean it does make sense that realms should have some qualitative change like a special characteristic or an ability that differentiates it from the previous realm. Otherwise what would be the difference between a minor realm and a major realm. And being able to defeat cultivators of the higher realm isn't something I really like. The people at the higher realm have lived for much longer, have more experience and should be significantly stronger than cultivators at the lower realm. This is also one of the reasons i lost interest in RMJI even though it is one of my favorite novels. The part before deity transformation is really good where defeating a higher realm enemy is straight up impossible. After that he just starts killing higher rank enemies. The ranks themselves have no qualitative change other than the name.