What happened is that Oda put himself in a corner he doesn't know how to get out of; and he did so when he had base Kaido one-shotting gear fourth Luffy after taking no damage. Now we jump to the current situation and nothing makes any sense: not only one emperor but two are facing the group, they all are suddenly able to hurt him (including the Scabbards) to a point of constant screaming on his part, and even in hybrid he hasn't been capable of one-shotting any of them (and Luffy has been exhausted for minutes!). If this doesn't sound inconsistent enough, Oda makes sure to blurry things even more by showing that he indeed can perform his thunder bagua so fast that a user of future sight barely dodges it. And let's not forget about Big Mom, who has done next to nothing even though her first showing of strength consisted on creating from the comfort of her room a storm strong enough to wipe armies out.
You guys can try to analyze this from a power level perspective all you want, but it's futile: the only reason why these guys are surviving that situation is because Oda wants them to do so for the "new versus old era" plot sake; and I wouldn't even be surprised if he just came up with this whole scenario while writing Wano already. I mean, you have too much faith on a guy who explicitly stated to improvise things on a daily basis and who didn't know how Kaido would be defeated —and I doubt he knows how to handle these characters even now.
A the end of the day, what we're seeing makes no sense and is a very clumsy management of the situation. Oda should have never made Luffy be one-shotted by Kaido and we're now seeing the consequences of his miscalculations and improvisations.