Gonna try to make a comment on this chapter and why I didn't like it.
I'm disappointed in this finisher and disappointed in the whole fight not because this particular chapter was badly done, but because the rest of the fight was.
See, during one (pick one) of Zoro's old fights the finisher might look something like this as well, but you'd have an, interesting, engaging, on-panel, focused-on back-and-forth romp preceding it. Zoro would be legitimately challenged and interact with his opponent's abilities in interesting ways (despite what you might hear, Zoro is, or used to be, more than "cut cut cut"). Take such a minor fight as his duel with Braham on Skypiea. Even in that fight he bled; he was legitimately pressed; his opponent was portrayed as respectable despite in truth Zoro being the stronger of the two by a lot. Zoro even gained a brand new technique to overcome him. Most fights would have more to them than that.
This is what made me emotionally engaged in Zoro's fights: the feeling of challenge and that the opponent was respectable, lending an air of credibility to it all. Zoro is a character who, more than most others in One Piece, thrives on conflict and challenge. Think of your favorite Zoro moments. He's at his best when he's seriously pressed and facing danger undaunted with a bloody smirk, isn't he? Even in "lesser" fights Oda would always use to creatively find ways to challenge him. When he finished his enemy with some flashy move it wasn't the flashy move that made it satisfying; it was the way he overcame what felt like a legitimate and respectable challenge.
But with this battle, from the very outset, Oda pushed the far less interesting, arrogant "You're-not-in-my-league"-Zoro on us. From the moment he 1080 PC'd Pica's shoulder and said that line with that face, you just knew where this was going. In my mind that was the step that doomed the fight.
It's more excusable when he went this route with a guy like Hyouzou, who was genuinely a big fish in a small pond (I hope this is considered an acceptable context to talk about Pica and Hyouzou at the same time in). But who is Pica again? Quick recap: he's a top-level subordinate of the Conqueror's Haki-using "most dangerous" Shichibukai who is the villain of the longest One Piece arc ever and is, mildly put, strong as hell. Pica's introduction consisted of him saying he'll take out everyone on the island and then coming out as a mountain-sized golem that even Fujitora noted how it seemed to be dangerous. Simply put, there was absolutely no need or really a good reason to portray Pica as such a chump compared with Zoro and go the whole "you're out of my league" way with it. But that's what Oda chose to do and, for me, that quickly killed off any semblance of a feeling of tension and challenge that could've been in this fight. Seriously, Zoro's fighting a man the size of a mountain with all the necessary credentials on paper to at least give him a pretty tough challenge. But we just couldn't have that. Instead he's just been a glorified nuisance as Zoro so pointedly noted after cutting through his oddly out of nowhere all-body Haki hardening.
I don't go wowz for Zoro because he takes out glorified nuisances in a flashy way. I love him because of his insistent locomotion no matter the challenge presented. The challenge makes Zoro. If there's no challenge, there's hardly a Zoro. And that's what I've found to be a problem in these 180 chapters (that's nearly 1/4 of the series…) since the timeskip. It doesn't feel like Zoro. It feels like some poor copy of his least interesting aspects.
Since critique should be constructive, if it wasn't fairly obvious, what I would've wanted done differently is for the fight, and Pica himself, to be portrayed as much more of a genuine challenge to Zoro. He wouldn't even need to get that much more injured (as in, at all) or worn down by it. Like I said, the Braham guy, much more of a mook than Pica, in Skypiea pushed Zoro more than this. The Whiskey Peak bounty hunter pack arguably pushed Zoro more than this in terms of the depiction of the fight as a challenge, a genuine test, a threat.
I'd also really, really like to have seen the fight be done in a fluid motion instead of this 25-chapter bit-by-bit thing. I think it would've improved the presentation a lot as we'd get the chance to "settle in" to it a little more. But I'm not going to rag on this chapter specifically for that as that's an issue with the overarching story structure and execution of Dress Rosa.