Anyone thinking that Koby will ever be stronger then Prime Garp in strength is insane lmfao. Mind you, we are 1100 whatever the fuck chaps in this manga, and Oda is hyping Garp and the old gen more then anything. Dude has 3 yonko running away from him, Koby gets saved by Teach from Boa Hancock.
Only Luffy and maybe Zolo are surpassing the old gen