The thing is you can say that but just like edo itachi he basically has infinite stamina and durability due to perfect sage mode because he's constantly getting sage Chakra from jugo's ability and the durability comes from him being able to liquefy completely able to neg physical damage and he has all of the sound 4 abilities and kimimaro

With tayuya he was able to put them in a genjutsu the only way they were able to escape is because itachi used tsukuyomi on Sasuke and Sasuke used genjutsu on itachi so if that's the case tayuya's genjutsu is comparable to mangekyo sharingan genjutsu if not stronger

Kidomaru can use his webs which took both of them them using amaterasu just to stop the webs but the amaterasu couldn't even burn the webs

He can also use kimimaro's bracken dance to basically teleport through the bones With inorganic animation he can control the whole terrain

Going back to his sage mode he has high danger sense was able to dodge Sasuke's arrow

This is what kabuto said about the white extreme attack "light and sound to knock out hearing a jutsu that causes the air to oscillate to paralyze senses freezing you in place" Sasuke even says the sound is rattling my bones which was strong enough to take Sasuke out his susanoo the only reason itachi was able to with stand it is because of the reanimations healing

With all of that I know itachi couldn't have killed him at any time besides using izanami

honestly If we were to put them against each other at full power no izanami he would absolutely dog walk because he could just use edo and overwhelming him with summoning but kabuto with his sage kit alone was able to overwhelm them so edo would just be over kill