@rawrfizzz:
I thought I explained it pretty well in the part you highlighted. Being free and following a prearranged destiny are kind of polar opposites.
Destiny is the story you write moving backwards. It does not take away from the freedom in the choices you have made along the journey.
In this particular case: we both have no clue who Joy Boy really is and what his prophecy truly might be – but we can agree that there seem to be different possible candidates that could accomplish it. Kaido says that "Luffy couldn't be Joy Boy either". Becoming Joy Boy is therefore something that you do, not something that happens to you. Luffy could have given up along the way, in nearly every single volume of the manga. He wasn't handed "power"; what became his advantage early on in the story, his devil fruit, was initially something that held him back and almost crushed his dreams (see both Luffy flashbacks).
He got lucky at times; yet one could argue that he created his luck through his kind spirit/compassion that helped him recruit loyal and driven companions. The kind of kindness that made a boat repair itself and cross the sea to save him and his friends. That made an old enemy sacrifice himself for him not once, but twice. That gave the most ambitious character of the story the resolve to give up his life for him (Zoro). Etc.
We tend to forget that he got awfully unlucky too. One of his brothers happened to cross the path of a Celestial Dragon on the first day of his pirate career. The other one forgot to learn haki despite spending years in the New World. Etc.
@rawrfizzz:
Also why would I respect Naruto when I clearly think it's bad? No.
Perhaps Naruto is not your taste. Doesn't change the fact that it is a genre-defining manga and deserves respect.