Imagine in front of you a Yonkou commander who defeated Queen, a Veteran lvl character like Franky and you threat both like fodders...
And that after facing a Yonkou over a hour, fighting both G4+G5 forms..
What Oda need to do more to show that non strawhat is ready to face Kizaru except Luffy and maybe Zoro(and even he would lose)..
Watch out this is just the beginning, Kizaru got finally the order to kill them all, with the navy beeing in danger, Kizaru will go all out soon.
People are not ready for the crazy feats with BOTH Luffy&Kizaru pull out soon, no one need to downplay any one of these two.
The last one will see why Kizaru is the main threat for now, the ancient Giant will hold down Saturn for good until Luffy vs Kizaru goes into a totally mess.