@MJR.:
There were some people who trief to convince me that this chapter will be great.
Oh well I'll keep trusting my gut feeling lol
You haven't read the chapter, or are you talking about this weeks chapter? If the former, then depends on your opinion of the characters it focuses on. At best it's a little heartwarming. At worst you will hate the chapter. If the latter, do people have a reason to believe next chapter will be amazing or do you have a reason to think it will be bad?
Cabbage and Romeo versus Gladius was basically a two chapter fight and easily in my top 5 for the arc. Kyros vs. Diamante also received a couple scattered pages instead of just the quick check-up panels, but it was less entertaining for a variety of reasons.
If you consider that two of the Donquixote members were defeated by gladiators they barely even fought at all then yeah, a lot of those fights lacked development.
By two chapters, do you mean one where Bart allows the others to go on and stays behind with Cavendish and Robin, where the other is where the fight finishes? To me, only the chapter where the fight ended seemed like where it was an actual fight, and the other was banter with maybe one blow exchanged. So much happened this arc that I don't remember everything, so I might be forgetting something else that happened. Either way that fight was lots of fun.
When it comes down to it, most fights were short with little attention when it came to non straw hats or arc specific characters. Zoro started his fight against Pica very early then had panels in various chapters to the fight, then a few chapters to finish it. Franky also started his fight early, had panels and another chapter or two dedicated to it before the final blow. Kyros had some scenes then a chapter or two focus. The rest had about a chapters worth dedicated to the fight.
This is where we can pinpoint some lack of development, as most development from fights come from straw hat fights. Going back to Daz's example, the Robin and Yama fight, we got development about her personality which became essential for the next arc. If we want to look at this arc, Usopp developed with that sniping moment which was quite huge with his skillset as well. The moments before were also for leading up to that moment. Then look at Sai, where we get some development from him, but to us readers it doesn't matter as much because he's not a straw hat, and not being arc specific he wasn't built up for that moment, so while cool it doesn't stand out as much.
In the end, I feel the fights allowed for certain developments, but a number of them didn't feel as great because of lack of development early on. We can argue whether Oda should've built them up some more or not, but for what were essentially tertiary characters, I thought it was quite good overall. Sai especially when you consider what he did after the fight against Lao G, which was muster up the remaining gladiator strength and lead them to push against the bird cage, as well as help the citizens get into the central plaza by taking out the remaining mooks.