He literally hasn't bro, that's the entire point. Washed up 80 year old Gaban that did nothing else but jerk off for decades casually outdid enraged Prime Rayleigh at his strongest, what do you want me to say ?
I literally would have to deny what's on the panels.
Well lets start with the at this strongest
This is what a Rookie AdvCoC Users Finishers (One of and not the strongest) Attack Looks like
100 Times bigger CoC than Garp's Attacks
But this Guy who is literally portrayed as CoC master, pinnacle of CoC, has CoC Leaking out him when he walks is gonna use his strongest attack and his no CoC??
Maybe just use your brain and realize Rayleigh used only as much strength needed to dispose of Sommers as he needed which is maybe 5%
He took the guy out
Luffy was also angry at Bellamy doesn't mean he used his strongest attack
Gaban used multiple Attacks
CoC
to accomplish same thing Rayleigh accomplished casually