Well you made a point in one of your previous comments about Roger and Whitebeard and how Whitebeard became known as the "strongest person" only after Roger's death.He does no question about it but at this very moment Kaido is the strongest since we don't know anything about BB and how he got stronger over these 2 years.
So wouldn't Kaido be labeled as the "strongest person" after Whitebeard's death? Instead he's known as "strongest creature."
So the title for "strongest person" can be held by someone else.