I don't think that some of them are even comparable now tbh.
Both Big Mom and Kaido got their own arc, which basically explained everything about them, like their backstories, personalities.
Every single Admiral still to be explored, we don't know in depht their backstories, their own justice and maybe not even their personalities in depht.
I'm not gonna lie, until now, Big Mom is the most poor written top tier character ever, the way that at the same time that she seems OP, she also seems very pathetic, considering that she got humiliated in so many ways by not so powerful characters, is so annoying.
The exact same thing can happen to the Admirals, that are so much more hyped than some Yonkous.
tbh the Broccoli Charlos is pretty much this case, he looked pathetic af with the Blast Breath + Shanks.