Those titles literally are jokes
They did not go to a tournament and beat everyone there to get those titles. It's all hearsay and speculation from common people
i dont know how you get 1150 chapters into one piece without realizing every single thing the public "knows" is government-approved or propaganda, and "the world" isnt really that big, because you have the main villains thinking they live in heaven above the world, you have a whole space and multiple planets thing mostly off screen, you have the world confirmed big enough that random admiral-level people are just found during a draft, you have a ton of confirmed unexplored islands/uncontacted people etc.
These titles are just shorthand so you know nobody in the blues or paradise are beating these characters in 1v1s. They're all top tiers in the world if you don't count the actual rulers of the planet who rule by force, sure