Because Oda doesn't show it every time lol.
However, and Idon't want to be rude, but claiming that 1026 Luffy has vene remotely better haki that prime Xebec, Harald, Garp or Roger/WB of GV (40 YO dudes) it's beyond dumb.
Let it go. Skysplit it's was always mkerely a pirate thing. The moment the super clash Harald and Xebec had and didn't happen, it was already dead.
Again are you even reading?
Sky split doesn't mean stronger AdCoC.
But refined AdCoC.
Luffy and Yamato didn't Split Sky before they didn't have refined " AdCoC ".
Kaidou comment on their AdCoC is crude as of now.
Between 1013 and 1026. There is no haki bloom for " Stronger Haki. But enough time to grasp the situation and Use " Haki " properly ".
- Roger and whitebeard in god valley. No Conqueror trails.
- Roger and garp, no conqueror trails.
It's really not that tough to understand.
Garp and Roger Most likely split Sky later in life.
It's not a " Pirate thing ". It never was. It's AdCoC. CONQUEROR THING.
WHICH NONE OF ADMIRAL POSSES OUTSIDE OF Sengoku and Garp as of now. And we don't even know if Sengoku Conqueror is even advanced or not.