Would a "tether" as a new type of CC be beneficial to the game?

Tether as in a leash, so to speak. Point A is a fixed location, the "leash" is a specific length and target champion cannot move outside the radius, but can move freely as long as the leash doesn't go taut?

After some thought, I realize cataclysm is a little similar, however, it's absolute, as it creates walls, whereas tether could be attached on another side of a wall, limiting your movement to the edges of the other wall for a small duration.