Haven't seen the OP movies, but aren't those pretty much like with DBZ's movies or Pokemon's pre-ICY?
The current situation with One Piece movies is... convoluted. Since the tenth movie back in 2009, the movies have stopped coming out yearly, coming instead like every two or three years, and the author of the manga is at least somewhat involved with the story of each one. (Except for 11, which is little more than a 30-minute chase scene animated entirely in 3D.) Movies 10 and 12's antagonists even explicitly exist in the manga's world...
...but none of them fit into the manga's timeline. Some claim that movie 10 was meant to take place shortly after the Thriller Bark arc, but there are several points in the movie that contradict this, most notably the fact that Zoro actively participates in the action of the movie despite the fact that at this point in the manga he was still recovering from some
severe injuries, which was shown to basically prevent him from being able to fight at all... Also while Shiki, the movie's antagonist, is actually namedropped in the manga, the fact that Luffy defeated him in battle is completely ignored even though the character who namedrops him
knows that Luffy did this and it was super relevant to the conversation taking place.
Then movie 12 would have to happen during a break between two major arcs where the story of the manga really does not allow for any additional major events to have happened, (the anime
kind of allows it because they changed some stuff, but even there it's a bit of a stretch) and movies 13 and 14 just flat-out don't work at all, for the simple reason that it shows all of the Straw Hat Pirates sailing together on the Sunny, when there was a several-year stretch of the story where the crew was forced several times to split up into two or more groups, and there was literally not a single point between late 2013 and... mid-2019? where all of them were in the same location.
Yet the thirteenth movie clearly presents itself as being a story set at the same general point in the journey where the TV-series was at at the time, making references to Luffy recently having defeated Doflamingo in a way that very much made it sound like that was the
most recent and most relevant thing he had done.
And then the fourteenth film seemingly throws all logic to the wind and just goes "THERE'S A MASSIVE PIRATE FESTIVAL GOING ON AND LITERALLY EVERY SINGLE CHARACTER FROM THE MANGA IS HERE, YAY!!!!" which is certainly a ton of fun but there is absolutely no way to fit an event like that into the actual series timeline.
...I think it ultimately comes down to the problem of them wanting the movies to feel up-to-date with what's happening in the show and feature the latest characters and abilities and all that stuff, which makes sense, but also having to wrestle with the fact that as the story went on, it's gotten more and more interconnected in a way that doesn't really
allow for "We are out at sea together and oh look we happened across this random interesting island what kind of crazy stuff awaits us on it?!" type stories to be slotted in between canon arcs anymore.