This basically. MS Kakashi > MS Itachi when Kakashi mastered his own MS in the War Arc, Kamui can warp away Susanoo or Itachi in the Susanoo, outspeeds or warps away Amaterasu, and can act without Kakashi meeting Itachi's eyes and so being hit with Tsukuyomi. Kakashi has also more chakra and by feats is faster and with better reflexes and taijutsu, suffers less MS usage drawbacks (he can spam Kamui without dropping his performance in the War Arc while Itachi feels exhausted for some seconds after he uses the MS) and far better ninjutsu; Itachi is better only in genjutsu and that won't be a factor, 3T genjutsu wasn't enough even against Part 1 Kakashi, and Kakashi can just avoid to be caught in Tsukuyomi, as he has full knowledge and a lot of ways to take advantage of that.
Healthy Itachi is exactly the same, just that Itachi doesn't drop when he uses MS; but he still is prey of Kamui GG.
If it's no MS vs no MS, I'd say:
3TS War Kakashi > 3TS Shippuden Kakashi >= 3TS Itachi > No Sharingan post War Kakashi > 3TS Part 1 Kakashi > Base War Kakashi >= Base Shippuden Kakashi > Base Part 1 Kakashi = Base Itachi
War Arc 3TS Kakashi vs 3TS Itachi it's a sure win for Kakashi, who is faster, has better reflexes and taijutsu, more chakra, a far more powerful CQC output (Raikiri, Raiden, Rasengan, Raikiri infused weapon) and trickery and mid range options (Raiton Kage Bunshin, Raikiri extended in Raijuu Tsuiga, Doton underground, Suiton + Raiton combo) with also favourable elements and more mastery of said elements (Raiton, Suiton, Doton vs Katon and Suiton, and by databook Kakashi can use all the elements, even if that maybe is referring to Rikudo chakra enpowered Kakashi), and can hold his own against Itachi's genjutsu (since even part 1 Kakashi was deemed for Itachi to immediately use Tsukuyomi to be beat, as 3TS genjutsu wouldn't suffice; and War Kakashi was on par with Obito in a genjutsu battle, Obito could control even perfect Jinchuuriki).
Then DMS Rikudo Kakashi obviously shits on an army of Itachis lol.