Luffy himself do not support a thunder bagua, he tried to dodge it and looked concerned when Kaido was going to to it.
He managed to dodge some of it, hence why it only knocked him down the ground and made him bleed from the head a little.
t was like I said, zoro has an observation haki inferior to the current luffy and a lower speed (SBS oda).
And barely managed to dodge, he was still caught (Luffy).
The other characters on the roof do not have the same capacity as Luffy at this point, look KID he is big and slow, zoro and killer does not have FS and speed> Luffy.
Law I'm going to give the benefit of the doubt to his teleportation, but he doesn't have a suitable FS (on the same level as Luffy), you know?
after kaido enters his dragon form without being able to use the divine diagram, Luffy uses g4, a slower and potentially stronger form, which kaido base with his diagram can hit him with.
Oda is prolonging the fight on purpose.