Anime / Manga - I refuse to believe there ever was a time after the Sayan saga when Goku wasn't the strongest sayan in existence

Luffy was dubbed the fifth emperor of the sea and is part of a plot to take down Kaido. He mastered his body and developed his Forth Gear. He managed to use observation haki to briefly see the future. He has his extended fleet and tons of allies across the world; including members of the revolutionary army, Fishman Inland, Alabasta, and one of the former warlords.

But no, I guess he hasn't done anything.

Why is Luffy asking asking about still achieving things? He just recently in the manga got the hang of a new type of Haki, been declared the unofficial 5th emperor of the sea, a new form and still more to come.