So I was reading WCI again and now I've got a new agenda.
Katakuri after gathering his cool, low diffed Gear 4 Boundman. And Gear 4 Boundman was destroying Doffy in Dressrosa.
Keep in mind that Fujitora couldn't low diff
base Luffy even after using his strongest attack to this date. Not only that he complemented Luffy on his strength and saying he was strong to fight him.
So that simply means:
Katakuri>Fujitora