The guy has the title of strongest, the other two guys had attributes superior to any other character.
Kaido has the greatest durability in the series.
WB possessed the power to destroy the world.
Mihawk probably has the peak of swordsmanship, meaning he is capable of cutting literally everything.
We saw in Marineford Mihawk with a random attack cut an iceberg, he will probably have the highest AP and DC in the series, I wouldn't be surprised if Mihawk could cut an entire island.
Now, imagine an Mihawk named attack with ACoC+ACoA, it will be insane
Also, I don't doubt that Mihawk has the best CoO in the series, since Shanks needed to create a technique that bypasses the CoO.