You say that about literally everything that happens to her tho
Because nothing happened that should be understood as the end of Carrot's journey.
- The side line of wano can be explained because Carrot's story is a little bit different with the rest and it was balanced by her treatment before Onigashima
- The defeat of Carrot is actually a VERY GOOD things that can happen to a character to create inner conflict, so this is not a minus
- Carrot becoming a Ruler is technically not a bad thing IF it is followed by the proper characterization
- Seeing Carrot in this chapter is actually a good thing since her appearance enters in parrallel with the one of Momo, and we know that both countries can (to this day) be the only one to survive the flood. Plus, Carrot is about to hear a few thing about the history of her tribe.
So in consequence, we only have ups, and no down. There will be a down if Carrot explains that she is happy on Zou. Then yes, it will enters kinda in contradiction with her characterization during her journey. But right now, we need patience, because her journey is not completely over.