He's only losing Kamui and Lightning Blade Accuracy at least.
He's losing Sharingan's basic Perks at most. TBH, He only kept up with guy because of Sharingan.
Honestly, Kakashi was a Bad Ass Ninja without Sharingan.
Kid Kakashi > Sharingan Kakashi any day. Kid Kakashi was so unique and original. I mean, his father was powerful without Sharingan. It's like when Kakashi got Sharingan, he lost the Hatake Pride.
I don't believe that needing Sharingan for Lightning Blade accuracy BS at all.
How come Naruto hits all of his Rasengan and he doesn't even have Sharingan?