Wouldn't be so sure of that. Katakuri is the only character in the entire series that Luffy achieved victory over because they submitted, and admitted defeat.
Katakuri got back up before Luffy, and could have easily finished him off while Luffy was still recovering from G4, but chose not to. There is no telling how much longer Katakuri could have continued fighting for, had he chose to keep fighting.
If King truly loses to Zoro in a 1 v 1, in not even a fraction of the time Luffy and Katakuri fought, and King can no longer physically continue the fight, then Katakuri > King