I didn't know that Kaido was all knowing, my mistake.
19 year old Luffy was never compared to Ryuma. Only Joyboy was.
If you want me to go into further details we go talk about the fact19 year old Luffy never defeated a 100% Kaido in a 1v1 fight. He plenty of help along the way.
Luffy is Joyboy thanks to the magical fruit he ate. That power and strength all comes from the magical fruit.
Zoro is a Ryuma descending who is set up to become the second coming of Ryuma my thanks to his own strength and willpower. Not just because he has a strong lineage.
Know and understand the difference.