Bruh are you for real? Kizaru had to kill his best friend and you're coming up with this cope?
Yes, Luffy has offered to help Zolo, then a moment later, Kizaru outpaced Luffy again. You don't seem to grasp that Luffy was the one trying to stop Kizaru from killing Vegapunk. Kizaru followed his task the entire time and after he was done with it, to the point when he had a mental breakdown, he gave up the fight.