After that first initial push, your are about 5 miles away from him, you and all your ninjustus aswell. Then with those five seconds you have to deal with the other 5 all coming at you, our protecting each other.
Lol don't include that naruto has Nine-Tail (close to infinite chakra). Like I said before, Naurto only won in the end because he out lasted Pein, combined with Talk no Jutsu on Nagato.
Itachi doesnt have talk no jutsu, nor infinite chakra.
He pushes you and all your shit away the moment the fight starts. And all the long range shyt you throw he absorbs. Pluss all he missiles he shoots(im sure is avoidable) but time consuming.
And again, why did it take Naruto/Bee/Itachi to seal the one Nagato. (i understand sealing is kinda harder than killing but w/e).