Im just putting it put there that whatever agenda you have against Admirals, Gorosei or Yonko, please consider the context of what might happen here.
Yes, its fucking disappointing what Oda is doing to an Admiral who doesnt show more than 3 moves and for some reason, cant match Luffy's speed. Maaaaaaybe he magically gets serious next chapter, but consider this: Saturn ideally cant lose now this arc, not when his 4 other contemporaries are now here to shut down whatever Vegapunk is trying to broadcast.
So then I ask: If Saturn cant lose because the others are here, is Luffy not supposed to win against anyone this arc without a finishing move? Outside of people clearly out of his league pre-TS, when has Luffy ever started a fight that he hasnt finished?
Im not saying Kizaru has to be the next God King of the story, but it still doesnt sound like he lost this chapter, be patient.