- Kakashi can't win against Tsukiyomi at all. As only the person as the same blood as him can defeat it or break it:
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. He can easily kill Kakashi with this alone. So he's not resisting or finding any counter to anything as you suggested.
- He's not finding a way around Yata mirror, and Sharingen can detect chakra behind solid objects as well, as shown by Sasuke in his fight against Kabuto, so any underground attacks working against Itachi is not happening and he's not finding a way around his sussano.
- Kakashi's raw speed is no where near Raikage's, so he isn't dodging Amatersu which goes exactly wherever the eye is focused.
- Kakashi's kamui is not instant, only the warp point is. If that was the case then he would've had done something with at least a part of Mezo's head, before Obito outsmarting him at that point. So Kamui being the answer to everything is you using your usual logic.
- Kakashi didn't win against Itachi in part two. He's only using 30% of his chakra, didn't even use his sharingen jutsus as he's nearing the end of his eye's life.
- How is he countering Yasaka Magatama and Sussano sword? Magatama being a consistent projetile attack throwing several ones strung together and his sword that was strong enough to easily cut through Kimimarou's bones that are harder than tempered steel? Don't give me 'he'll kamui it' again. You know it isn't possible.
Itachi wins this low to mid difference.