I don't really understand the criticism of the fact that the story was halted because of a few battles.
There's slowing down for fights, which shonen manga are all about. Heck, its why tournaments happen so often in so many series.
And then there's coming to a dead stop for a solid 50 chapter year to do nothing but fight in one location.
There's a reason Oda hasn't given every member in the crew solo extended fights in any arc since, and keeps dividing the teams up. It's death to the pacing. He can do that again for the final arc of the series, because it's the finale. But until then? He settles on two or three of them getting a fight, plus Luffy, while everyone else gets support roles or much shorter skirmishes earlier in the arc.
Not counting the fishman island battles because those were all super short one sided "lets show off the timeskip powers" fights and combined were all done in just a couple chapters..
Technically a fight stops the plot and if the author wants to make it a bit flashy and interesting it has to last more than a few pages.
Otherwise we have the mess that is the Marineford arc with the action cut every page and the constant skip.
Marineford wasn't about showing definitive fights to the finish. It was about getting to Ace… and hyping up and showing what the strongest in the world guys could do, and just how far Luffy had to go. It was a tease. "Look what Mihawk can do, Zoro is going to fight at that level later!" "Look what Doflamingo can do, he's dealing with Crocodile like he's nothing!" "Look at how easily Jinbe takes out the boss of the previous arc!" "Look at how scary all the admirals are!" "Look what an old sick Whitebeard can do, imagine him in his prime, and what BB will do with that power!"
Its was the midpoint, not the climax. Had Oda showed ever single fight there from start to finish, we'd have been there for like six years, like the final arc in Bleach. We're probably going to see a lot of those big players doing their all out to the finish thing at the end of the series.
Maybe at that time One Piece was not 100 volumes long and every arc didn't last 2 years so it felt long but having reread it recently it didn't bother me.
Nah, that's why Skypeia felt long and out of place at the time. It was a two year arc during years 5 and 6 of the series, that had no apparent connection to anything, so it was a little awkward and easy to see why people were annoyed then, and now in the context of 20 years and counting its nothing.
Water 7 as a whole, the length was fine. Everything in the city and after was interesting and moved at a good clip. ANd then…. they got to EL.
If Oda had skipped some of the musical chairs in matchups, or so many of the fights didn't end with new powers made up out of nowhere, or made some of the fights even a few pages shorter, or introduced one less CP9 member so that Franky didn't need to get in three different fights (plus Chopper) he could have trimmed 10 chapters off and it would have flowed better maybe. Similar issues come up a lot, like when the crew is running from a death cloud for half a year, or with the Big Mom chasing the crew on the water which went for months and was really repetitive.
Oda goes where his creativity guides him and some times that leads to some bits going longer than they maybe should have.