People keep underestimating Sanji's strength so I'll post this here.
Sanji's strength feat:
First thing let's see when Sanji kicks Oven. Sanji broke Oven's neck. See the sfx when Sanji kicks Oven.
See also that Sanji's leg is not black even though he wears white pant and shoes which indicates that Sanji doesn't use armament haki.
This is the same sfx when Queen cracks BM head
Oven also gets bruises after
1 base kick from Sanji without armament haki and DJ
Note that in Vivre Card Oven is said to have the highest durability among Charlotte sons
So basically 1 base kick from Sanji without armament haki breaks a neck of someone who has higher durability than Katakuri. Sanji's physical strength is not to be underestimated.