Robin was like the 3rd most important character outside of the SH in Alabasta wtf
Not at all. What Robin really did before she joined:
- Make it look like shekilled Igaram
- Gave a strawhat a log pose they rejected
- Stopped Pell
- Saved Luffy
- Stopped the marines at the door of the palace
- Brought Cobra to the Poneglyph chamber
- Attempted to fight Crocodile
- Lost to Crocodile
Here is what Carrot did before the end of Wano:
- Traveled with the strawhats
- Took the post of look-out during the arc
- Saved Chopper and Nami
- Tried to fight Brulee
- One shotted Brulee and her team
- Conquered the MIrror world
- Draw away to findthe strawhats
- Lost her mentor and tried to fight Katakuri in the process and lost
- Transformed into Sulong, saved the entire crew by managing to defeat an entire fleet by herself
- Helped Sanji with his guilt
- Saved Marco
- Fought Perospero and lost
Carrot is literrally ready to join the strawhats. The only she she will need after, is a two or 3 chapters of development like Brook.
But saying that Carrot is somehow not ready or irrelevant is
a complete ignorance of the story. The fact that most of the things here happened in whole cake...
... Doesn't mean that they disapeared magically !!