herez my teory : actualy sasoke isn't nerfed...koshomoto made sasuke look weaker delibarately in boroto manga..to show us that sasuke lacks curse of hatred to fuel his true sharingan powerz..Sasuke being nerfed isn't anything new. It's quite frequent to nerf characters in Kishi's writing. Although it is less likely to happen to Uchiha characters.
As for Sarada, there really isn't anything revealed about her or Mitsuki to say that they are nerfed. They are simply just forgotten (like everyone else in the series).