where'd you get that idea from? Friction is an essential force for an object such as a shoe.
Disclaimer: I know its video games and science really doesn't matter much to you, but I'll try a whack at it anyway.
[physics lesson] (see:
Newton's three laws of motion)
Sonic's foot applies a force at an angle into the ground while running,
The normal force of the ground prevents Sonic's foot from sinking through or breaking the ground, Thus any force applied downward will react upward. If enough force is applied, the reactionary force of the ground can overcome gravity for a short time, or a jump. It is an ideal method to minimize contact with the ground and deal with only air resistance as an opposing force while moving forward.
Since Sonic applies the force of his foot at an angle behind him, one of the resolved vectors points behind him.
The friction of the ground reacts to the force of the foot, keeping the foot from sliding back.
Since the force of the foot is applied to the ground at an angle directed behind Sonic, the reactionary force of friction will react in the opposite direction, forward. Since there is very little opposing force, a forward acceleration is achieved[/physics lesson]
(What I bet you're thinking:

)
A shoe is intended to amplify the reactionary force of friction with a tread on the sole of the shoe. I would think the intention of Sonic's shoes is the opposite of what you claim. Without extraordinarily high friction soles, Sonic would slip and slide rather than be able to perform the feats of acrobatics he has shown.
But of course this is video-games we're talking about; for all they care, they can throw-out the laws of physics and substitute their own if they choose. I'm really just nitpicking, don't take it personally, or even seriously if you choose.