Although it's quite clear that Kaido has been defeated.
But those citizen, not only them. Let's say the whole alliance, especially those Samurai who doesn't even see Luffy vs Kaido
But they are so admit to that Kaido is now fully finished and just go celebrate happily like it's over for real is very unrealistic and anticlimatic.
Imagine you knew how strong Kaido is, and how difficult just to beat that guy.
And suddenly an announcement make you believe he is defeated and just go on board with that lol in which they don't even saw his body.
The citizen esp don't even saw the battles and if in this chapter if there's no realistic reaction and just go celebrate with them, and just ok with them saying they beat that unbeatable monster who rules over them for 20+ years just a minute ago lol
It would pretty bad writing ngl.
It's borderline C- tier story endings