Story, pacing, fight scenes, animation, character designs, thematic and emotional resonance, it's smarter both in how the characters make their decisions, and the points Togashi makes when writing, I could go on.
What story?
Individual arcs or overarching because Togashi doesn't have a real overarching story, just individual arcs we want to see play out.
Anyways I'd definitely take One Piece's overall story over Hunter X Hunter, but when we get into individual arcs it gets a little trickier.
Fight scenes?
Undeniably from a strategy sense, so I won't blame anyone for preferring them, but I prefer the more fist to fist style Oda has and love his art/coregraphy, I'll take the ideological conflict with emotional high points a Kreig vs Luffy over much of Hunter and day,it's romantic.
Character designs?
Overall I'm taking OP character designs, Oda hasn't put out anything I consider as abysmal as the Zodiacs designs, and a large portion of his side characters designs bore me, which isn't to say they need to be wacky to interest me, they just don't hit me.
Thematic and emotional resonance, emotional resonance is definitely the more subjective of the two.
Themes? Eh, the only way I could see someone saying this is if they haven't grasped the overall themes of One Piece and the individual arcs, Oda's a master of bringing themes home with a single point and he does it arc after arc imo, like with the ringing of the bell in Skypiea and how it ties up the three overarching themes.
Write about what you consider it to be in Hunter and I'll respond with an analysis in One Piece so we could compare the two.
Smarter? It's certainly the more detailed of the two as to thought processes and strategy, but where I can see One Piece relying on vase character traits and impulse too much, I can see Togashi getting stuck in his head and making the characters seem too cold/detached, as well as forgetting he's working with a visual medium so everything doesn't have to be a novel, and that there's such a thing as too much detail.
In all honesty I see them both striking a fair balance.
What points that Togashi makes while writing?
I don't think anyone's being 'fooled' by anything. I know this may come as a shock to you, but some people may simply just prefer Togashi's style of storytelling and world building. No need for some deep analysis as if there were some objectively right or wrong way to tell a story.
I'm glad that you're enjoying it from the beginning, but I encourage you to stick with it because the story continues to drastically evolve over time.
I'm not saying there isn't much to prefer in Hunter X Hunter over One Piece, and I don't believe One Piece is a better series and vice versa, but through my experience, as my post wasn't necessarily aimed at you, Hunter X Hunter comes off as much more "intelligent" and "deep" on the surface in contrast with the much more traditionally Shonen goofy One Piece so certain groups don't actually give it real thought, which becomes clear in discussions with them on the two series.
