So as we know, at the beginning of Wano arc, Kaido defeated Luffy with a single blow. It is due to this scene that I believe many fans greatly exaggerated what it might take to beat Kaido.
Now granted that it will be a group effort to defeat Kaido, Luffy will end the fight in a 1v1 against Kaido. Before this 1v1, Zoro, Kid, Law and others will likely weaken Kaido to a point where Luffy can fight him 1v1.
However I still believe this fight ends in a 1v1 and will probably be more similar to Luffy vs Doflamingo than the Straw Hats vs the Pacifista.
Luffy vs Kaido in Act 1 was designed specifically to overhype Kaido and cement his position as the strongest foe Luffy has fought up until now. But the key thing that people miss from this encounter is this: in order to beat Kaido, it is essential that one knows Ryuo(the technique of Flowing Armament Haki). A strong fighter without Ryuo would actually fair worse against Kaido than a weaker fighter with Ryuo.
This is clearly seen with the Scabbards. Luffy is and has always been portrayed as much stronger than Kinemon. However Kinemon actually did better against Kaido than Luffy, as Kinemon knew Ryuo while Luffy didn’t.
Now things are different. Luffy not only has Ryuo, he has one of the strongest Ryuo techniques in the series, likely above even that of the Scabbards.
In fact Luffy is now able to utilize at will the higher grade of advanced Busoshoku, allowing him to send his Haki into a targets body and destroy said target from the inside. In addition, he has seemingly mastered Gear 4. He likely can use Boundman, Snakeman and Tankman as easily as he used Gear 2 and 3 at the beginning of the post timeskip. If he can do this, what is stopping him from combining Gear 4 with Gear 2 and Gear 3 or even inventing a Gear 5?
This isn’t to say that Luffy is Kaido’s level. But it is to say that if the allies weaken Kaido enough, Luffy could defeat him 1v1.