Wtf are you talking about? It's not like Guernika immediately died from that one attack from Kaido.
He still survived, took a picture of Gear 5 Luffy, and then sent that picture to the Marines.
After all of that he finally died.
So all that hype you are giving to Kaido for killing Guernika with a no name attack, is all for nothing when the guy was able to survive a bit more longer.
Also Guernika accepted his fate, so Kaido pretty much killed someone who didn't even fight back and let himself get hit.
Hey at least we saw Kizaru kill Vegapunk on screen and got his death confirmed in the main story.
Guernika's death on the other hand was debatable and at the end he died off screen, and his death wasn't even confirmed until his vivre card came out.