The trolls are out. Let's have some fun.
You're confusing Zoro for Luffy. Luffy what's the one who fainted from starving alone. Zoro requires poisonous food, follow up by starving, follow up by injury for him to fall. Luffy fell and almost died just from eating one poisonous fish. Magellen and had to spend 12 hours on the toilet a day from eating poisonous food.
People need to get on Zoro's level.
Comparing current Zoro to Oden in any way shape or form is pure fucking stupidity.
Zoro is much closer to Denjiro, who couldn't do anything.
In fact we have 0 proof he IS stronger than Denjiro.
Denjiro couldn't do anything to an injured Zoro. That's why he couldn't beat Zoro. Instead, his subordinates told us that Zoro was holding his own against him.
Oden is weaker than Mihawk and not near his level.
Everything about Zoro's character is meant to represent a samurai. His swordsmamship style comes from Wano, his teacher is a Wano descendant, all through his current swords were forge by blacksmiths from Wano. Even the data book as hinted at Zoro himself might be a descendant from.
The following scene makes it very clear that Zoro will kill and take Kaido's head. Ashura stated that Kaido won't be beat until they literally take his head.
Zoro is the only one strong enough to do that and at Oden level.
When Zoro cut Pica he wasn't using his haki to increase the strength of his attack. Yes, it will naturally make his attack stronger but that wasn't the main reason for using it. He was using it to make sure his swords didn't break. The was the purpose of the flashback. Now, we have seen a small taste of his haki power when he casually cut off a coastline using little strength from a seated position.