Having the characters talk to each other for a start.
Robin went to the Revolutionary army, spent time with Luffy's dad and *dead brother, and she didn't bother mentioning it or asking Luffy about it at all.
Nobody ever asked Zoro why he lost his eye and how. You'd think they'd care if he got some new enemy or maybe Chopper could offer to treat his eye for him. Hell maybe Sanji could even use it to insult him or something, instead its like it didn't even happen.
It really doesn't feel like the crew are actual characters OR that they care for each other.
I mean the characters clearly talk offscreen just not about
everything
For example, Luffy knows Zoro and Sanji can use haki right after the timeskip
How would he know that unless they spoke offscreen? Characters do talk they just don’t cover every base because then certain things just couldn’t happen
Certain things you brought up we either wouldn’t see for very obvious reasons (Oda’s hiding it intentionally), it’s just obvious, or it’s so irrelevant that there’s no reason to show it
Luffy doesn’t care about Dragon at all and has never asked any questions about him. Robin knows this so why would she ever bring Dragon up to him
The Sabo one is stupid I’ll acknowledge that for sure
Zoro’s eye scar is clearly being hidden from the reader and the Strawhats obviously would’ve acknowledged it offscreen. If anything it was acknowledged onscreen in Return to Sabaody when Sanji asks the guy about Zoro and Sanji has a shocked expression when he talks about Zoro having a new scar
When we
see the characters talking to each other it’s almost always going to be about something that’s relevant to the ongoing plot. Most of the things that people want just.. aren’t