Roger was PK because he was stronger than anyone that isn't named Whitebeard.
"WB could have taken the throne but chose to bow before it" from Doflamingo's own words
Kaido isn't Roger or Whitebeard
Kaido couldn't overtake an old and ill Whitebeard, Doflamingo,Bigmom,Sengoku,Garp all acknowledge that Old WB > Kaido
Whitebeard's death is the only reason why the Throne Wars is happening, Kaido is not PK material
[automerge]1605979430[/automerge]
WB did not become PK either so what?
If you remove Luffy from the story, BB becomes PK
If you remove both Luffy and BB from the story, NO ONE becomes PK