what makes you think like that, katakuri purposely lose to luffy who is now a yonkou, before he was said to be undefeated, the only commander.
Even if, by some miracle, Katakuri is stronger than King and Queen individually, there is no way he'd put up a better fight than them together. Katakuri is much smaller than Queen and he is made up of food, so of course, he'd get sucked way quicker. Saying otherwise is the epitome of ridiculousness.
It is dumb in the first place to even use the fact that they lost to an admiral as a reason to call them weak. It has only been a week since King low differed Zoro, who was scaring the shit out of BM and Kaido by raising his Haki—Something Katakuri can't even dream of achieving.