And Blackbeard who has no CoC yet is still being portrayed as one of Luffys final villains?
Kaidos point was literally disproved in wano when he lost not because Luffys haki got stronger, but because of Luffys fruit power awakening.
Luffy without Gear 5 was very close to beating Kaido.
Luffy with only Gear 5 wouldn't have beaten Kaido.
As I keep saying, it's certainly an advantage, even for Kaido it obviously is to become a half-dragon, but it doesn't matter half as much as their haki, fruits don't make them jump between tiers like haki does.
It's also the difference in their haki that puts Shanks a clear tier above an awakened DF user supernova like Kid.
And yes, Blackbeard who having two devil fruits including the power to destroy the world chose to run away from Akainu instead of sinking an admiral goodbye.
We will see what haki Blackbeard has anyway for having scarred Shanks pre-fruits. That's promising in that regard, but if he doesn't have any kind of strong haki my expectations of him will be low even with Yami's shenanigans.