
Gecko Moria is a pretty powerful fighter but you could argue that Luffy surpassed him early on. Gear 4 would likely make short work of him in the modern day. Gecko’s no slouch in the power department by any means but at this point in the story Luffy is both faster and stronger than Moria. When that’s the case it can always be very hard to overturn that. Gecko would need a significant power up in order to even start the discussion and good luck with that. Luffy certainly won’t stop growing stronger either. Luffy wins.