Board Thread:Theories and Speculation/@comment-31966672-20200409171208/@comment-25122992-20200412210600

I meant it as a benefit since Rasengan's lack of speed factor doesn't produce tunnel vision, as in case with Chidori, so you don't need any supplementary methods like a Sharingan to cover that weakness. That's the main difference between Rasengan and Chidori.

While it's true that Chidori can be used without applying speed and by catching someone off guard, it was still created based on this aspect. You have a better chance to catch off guard if you move faster, right? Take the example of Boruto's recent fight against Boro, only Sarada's Chidori was fast enough to destory Boro's core before he had the chance to react and hide it. Rasengan cannot do that, and as far as I remember, in the anime Jiraya even pointed out that your opponent isn't gonna wait to be hit by Rasengan if he sees the attack coming.