I was thinking about this too
In the past there were certain bounty milestones that Sanji didn't achieve timely while Luffy and Zoro did.
As an example:
- Luffy is the first strawhat ever to get a bounty
- Zoro is the second strawhat to get a bounty
- While Sanji received his first bounty alongside all the other crewmembers. He hit this milestone with other crewmembers, not alone like Luffy and Zoro did.
Another example:
- Luffy was the first strawhat to hit a 100+ milions bounty
- Zoro was the second strawhat to hit a 100+ milions bounty
- While Sanji hit this milestone with Nico Robin and Usop, again, not alone.
So I was thinking...what about the 1 billion bounty milepost?
- Luffy was the first one to hit it
- Zoro alone will be the second one to hit it
- Sanji will hit it in the future after Zoro, accompanied by other crewmembers, e.g. Yamato, Jinbe and Robin.
>First landmark: getting first bounty
>Second landmark: getting a 100+ milions bounty
>Third landmark: getting a 1+ B bounty
Disclaimer: I am not saying that it will be certainly this way, I was just considering this possibility and how feasible it was.
Maybe Oda will not consider this pattern at all, or maybe to him the third landmark is a 1.5+ B bounty, and not a 1+ B bounty