Sanji has atleast principles and he is the cook of the ship, he is also how a man should be, not like zoro who seem more shut off then anything, thats not being a man although i like zoro, sanji is man enough to show emotions and talks to his comrades, his development in terms of fighting is also more consistent then zoro.
Not to mention the fact that he is the cook of the ship yet still is able to compete with zoro who is swordsman of the ship, someone whos purpose is to fight and be second under the captain, Sanji is able to fill two roles of the ship, both a cook and a fighter equaling the fighter of the crew.
Sanjis dream is to find the All-blue, his goal doesnt motivate him to be stronger although Zoro being the strongest swordsman does, them being equal then says something about Zoro. Sanji is my 5th favorite so dont talk shit about him, hes respectful to women, not a kissass and he also respects Luffy just as much as Zoro but is not above correcting him when he gets out of line. He called him out on it when Luffy was about to tell Usopp to leave the crew.
