TL;DR at bottom.
Yesterday I was at Best Buy and saw the Blu-ray on a shelf. I decided to buy it on a whim, as I'd heard of it before and remember it getting good reviews. I'm no stranger to anime, I've seen Lucky Star, KonoSuba, and two of the three My Hero Academia movies. In particular, I enjoyed the MHA movies because of their World of Ham tendencies, and everything there is so over-the-top. So I thought if this film is anything like MHA, I'm gonna end up loving this.
I watched it blind, with little knowledge of the One Piece franchise. All I know is that they're pirates and they ate some fruit that gave them powers (or something like that). Anyway, it had the same over-the-topness as MHA, so that I enjoyed. But I was really surprised at how emotional it was, especially with Uta's motivations and backstory. No spoilers, but there were some themes involving death and the afterlife. I almost cried at the ending, too.
Overall, great animation, great music, and unique story. I might actually watch the series lol. I heard it was the highest-grossing film in Japan in 2022, and I think that title is well-deserved.
Shame on me for not seeing this in theaters when I had the chance!
TL;DR: As a newcomer to One Piece, I enjoyed this film because of its heart, animation style, music, and similarities to MHA.
My wife has been watching OP for over ten years now. I always talked shit about it but never understood it. After being amazed by this movie though, I finally decided to give the show a shot and am so far blown away by how timeless it feels. It definitely has a lot of the typical shonen tropes but it's mainly a comedy with continuity and it really excels in the regard.