Haki can get stronger, physical states can get stronger.
Luffy jumped from a low top tier to be able to defeat Kaido.
Of course G5 wont be looking stronger than Kaido when Luffy used it FOR THE FIRST-TIME.
That is not how it works.
Kaido is a fighter with great experince, great mastery of his df and haki moveset.
It would be bad if he was overwhelmed by G5 Luffy.
Like how Luffy learned FS but still Katakuri had a little better one.
It wont change the fact that both Kaido and Luffy got hyped equal when they both fought each other:
You saw how Luffy jumped tiers in just mera hours.
That wano Luffy, since Wano months pass, Luffy fought also strong opponents(Kizaru and Gorosei).
Means he got even stronger and the fact that he has now full control of G4 even in base show how much he improved and got stronger.
Means not just his G4 improved, but also his haki is now stronger and his G5 control is far greater.
Would be G4 enough to defeat Kaido?
Be honest nope, but I can see Luffy without G5 can legit push Kaido to high diff.
And now add G5, he wins.
He already did it.
He surpassed Kaido strongest attack and defeated him.
Wano Luffy did this...
Yes Kaido had a long ass battles with multiple characters, because that I place Kaido above wano Luffy.
But current Luffy is different, he can make Kaido enough exhaust to a point where he can finish him off with G5.
And we saw G5 was strong enough to tank Kaido strongest moves.
He couldn´t knock out Luffy and that is my point, Luffy could simple fight with G5 enough.
Ragnaroku wasn´t the reason why Luffy almost lost G5 transformation, it was because G5 drained lot of energy mate:
You see, it was just Luffy G5 was running out because it drained much energy, not because Kaido knocked him out.
We don´t even know what for weakess or durability Loki will have.
But fact is that he will face A STRONGER Luffy...
A Luffy who can now use better haki, better his Gears and awakening..
Challenging such a strong opponent would be already a good feat.
And Kaido in fact never knocked out Luffy in G5, if Loki can do it, it proves that Loki pose AP who are above Kaido one.
Hell he might even show a hakai feat who can surpass the one of Kaido&Big Mom together one!!
Oda is hyping the shit of Loki.
We need to sit down and just watch how strong this guy will be.
But you can agree, the hype this guy has, it means he will show some crazy feats.
And unlike Kizaru and the Gorosei who couldn´t fight all out because of plot(they will once they fight in the end war), Loki is free to show his true power from the beginning.
Loki will be one lvl above Oden, same Oden who give Kaido a good fight.
Im pretty sure if Kaido tried to do what he did in wano with the samurai, in Elbaf, he would be dead now.