Law did about what most would've expected of him given his performance in Wano. Not Yonko tier but can give them a good fight. Kids portrayal only makes sense if Shanks significantly stronger then every Yonko. Basically Shanks should be able mid diff Kaido and low diff Big Mom.
Problem is, if that's the case then emperors are not a balanced force. Its makes no sense for their reign to have lasted this long if Shanks could've easily dealt with them.
BB has lost all of his threat as well. How are we to believe that he can in anyway fight Shanks after the gap in their performances like this?