Yes, 4Kids' handling of the dub was that bad.
Obviously, to kids who didn't know any better, there was no problem.
But there were cracks and they would have been broken wide open if 4Kids had continued dubbing it.
The primary examples are cutting the Twin Capes arc (which introduced Laboon the Whale) and the Little Garden arc, these aren't big deals in a vacuum, but Laboon turns out to be
extremely important a few arcs later, and the Little Garden arc has even quicker consequences.
In Little Garden, three things happen:
- Sanji gets the crew the ability to reach Alabasta, their final destination during that part of the story, while also setting up his relationship with Crocodile (the Mr. Prince persona).
- Nami catches a dangerous disease, which is why they need to go to Drum Island, this isn't that big a deal, and can be plastered over relatively simply.
- The Crew meets Dorry and Brogy the Giants, which gives Usopp a goal of reaching Elbaf, their home island. It also has a payoff later on when the fact that they known Dorry and Brogy allows them to get two other Giants to join them in the Enies Lobby Arc.
The Dorry and Brogy and Laboon things are the
big missteps in 4Kids' handling of the show, fortunately, they lost the rights before the arcs where those characters became relevant.