Agree with above
His ability to attract powerful allies is the main reason he's come this far
Think about it
Zoro = CoC user, future WSS
Nami = One of the best navigators in the verse
Usopp = one of the best snipers in the verse, also very innovative (built his own "sniper", the climatacts, etc)
Sanji = one of the best cooks in the verse, also very strong, former prince of Germa
Chopper = one of the best doctors in the verse, also the only zoan user that has forms outside of hybrid and man-beast
Robin = Ohara survivor, one of a handful of characters in the entire verse that can read the poneglyphs, connected to the giants of Elbaf through Saul
Franky = one of the best shipwrights in the verse, his mentor is the one that made the ship for the Pirate King, had the blueprints for an ancient weapon
Brook = Great musician, solid swordsman, very useful ability, great at infiltration, decades of pirating experience
Jinbe = one of the strongest Fishmen of all time, currently the strongest fishman alive by far, represents an entire race, former Warlord of the Sea, well known and respected by some of the greatest pirates of the current era
You see my point