Kaido was in shambles in front of Zoro. The problem is Kaido's regeneration. Zoro can consistently deal damage to defeat Kaido in a 1v1. But because Kaido had the help of Big Mom. The consistent, extreme damage was removed from the equation. That's why Oda had Zoro missing and pulling his attacks.
Luffy and others all damage Kaido, but it's nothing as consistent as Zoro or as weighted as Zoro. Thus Kaido is regenerating from their(excluding Zoro) attacks fairly quickly, so it's all like nothing is even is happening to him.
Kaido basically has has endurance and durability, until met with a mighty foe(Zoro, Roger, Shanks, WB, Oden etc.