But still, there was Koby in the big double spread of the most important characters for the race.
Yeah, because the rest of the rooftop boys aren´t going for the OP, they´re just working for Lufffy. Zoro obviously so, and that´s what Kidd, Law and Killer´s destiny is.
But again, Law is the one who has the most build up since the timeskip:
starts the alliance at PH
Beats Vergo, who was basically the arc villain
is involved in the take down of
insane DF with 5 billion on the black market
Will of D reveal
Helped take down Big Mom
tragic backstory(pretty typical for the edgy number 2 guy in a shonen manga)
connection with Blackbeard and probably even Imu.
I honestly don´t see him as being lesser then Koby in the final war because he wasn´t in the character spread. I mean, Loki wasn´t either, and I see him being above pretty much everyone except like, Imcel. Shanks, Papazuki, Teach. And let´s be honest, Nepo piece>anything else, and Loki´s dad is pretty much the second strongest character excluding Imcel or other VC stuff