Zoro's Flying Dragon Blaze, a COA-based attack, legit scared the shit out of BM and Kaido while Yamato's COC attacks weren't even tickling Kaido. It wasn't implied nor said that 'infusing your attacks with COC' is an advanced form of COC. You need to actually upgrade or unlock your COO to the next level to be able to use FS while you need not make your COC stronger or unlock an advanced form of it to infuse your attacks with it. You just need to figure out the way to infuse your attacks with COC, which makes your attacks exponentially stronger.
COC is just as beatable as any other ability—we've already seen non-haki users beating Haki uses, Non-devils-fruit users beating devils fruit users with broken abilities, non-awakened users beating awakening users, et cetera.
I did not say Rayleigh and Garp don't have COC; I said their COA might be able to overpower COC from someone like Yamato. No one or nothing hinted at Rayleigh using COC against Kizaru so he wasn't using it until further notice.
But this has everything to do with attack types and nothing to do with Yamato's CoC somehow being inferior in power.
Kinemon and freakin Kiku could hurt base Kaido with CoA coated blades, whereas Luffy in Boundman couldn't do shit to him. Kaido is just super resilient, as he has a very massive and tough body, therefore making him highly resistant against blunt force attacks.
Boundman still >>>>>>> to Kinemon or Kiku or any other scabbard for that matter in actual attack power.
The actual hype within the Yamato TB scene stems from her being able to hurt Hybrid Kaido, even tho it's a blunt force move. Up until now she's actually the only one who achieved that, all others either needed CoA/CoC infused blades or CoA/CoC internal destro haki blasts.
Give Yamato a sword and she would have insane DC feats and would easily be able to damage even Hybrid Kaido severly.
Higher attack efficiency via something like lethality =/= higher attack power. Her attack type is just "inferior" in that case.