Sweet summer child, you are still fooled by the narrative...
Zoro never runs out of haki, it is Luffy who does.
Fighting Kaido for 20 minutes is what you wanted to say because that's how long he can fight. Not that 200 hours would make it any better when facing Zoro who can one-shot him any time.
The rooftop where Zoro has shown that his captain is a mere weakling compared to him.