Board Thread:Naruto Discussions/@comment-26107879-20181004003653/@comment-37328019-20181104034720

Chidori is a lightning jab. Raikiri is a faster one. The show deals quite a lot with the concept of exertion, this is a very draining technique because Kakashi is exerting 100% of his speed. Which in turn grants him tunnel vision (he's running at his body's maximum speed which is faster than his own perception) causing Minato to tell him to abandon the technique. The jutsu's power is directly related to the users speed. Simply covering your hand in lightning is not a jutsu, kid Kakashi could only generate enough power to make chidori an A-rank jutsu by increasing his momentum strengthening his lightnig jab (increased momentum = increased destruction, this is what makes Raikiri S-rank as opposed to chidori's A).

... if chidori increases Sasuke's speed how fast is everyone who has grabbed his wrist while using it, Itachi deflected it into a wall then broke Sasuke's hand, Kakashi redirected Natuto and Sasuke's attacks into water towers

That being said the cutting nature of chidori would practically erase wind resistance (drag) so they would apear to move faster as their speed would no longer be dampened running into air molecules.