They steer his ship sometimes for better or worse:
- Supernova was an absolutely great idea to diversify the rivals aiming for PK. How they've all panned out (outside of Bonney and Urogue) is up to the reader on what they wanted from the story, but I think his focus in two of them (Law and Kid) has been great. Bege also has been great.
- Them forcing him to do something special for chapter 1000 was really not great. Sure, we got the rooftop fight and I'm glad it exists, but in retrospect, it seems to have caused the raid to be much longer than it was with how he had to move characters around after, etc. More focus could have been given to the F6 instead of rooftop battles (though I do agree that really the Yonko needed those exposition moments anyway)
Just 2 of the obvious examples (I really don't know many tbh), but Oda in general just has a terrible time balancing tons and tons of characters. It is 100% his (and One Piece's) achilles heel. Dressrosa had this issue, so did WCI, and Wano is by far the worst offender.
Luckily the series is heading towards for more important/bigger characters as it nears its end, but guaranteed the final war will be extremely and overwhelmingly long. It will very VERY likely eclipse Wano by a country mile (I could see it being 200-250 chapters, no exaggeration), depending on the number of characters it involves and the buildup.
Nearly every long-form story-teller has difficulty with their ending as they try and close their character plot and storylines.