Most dog toys are made for either solo play, like treat puzzles, or for playing a game that requires a human to be involved, like a tennis ball, which requires a human to throw it.
When tugging a rope, dogs can enjoy a fun game between the two of them, while showing their strength. Even though tug-of-war is a fun game for any dog, beware if you have small dog as well as a large one as the larger canine could easily injure the smaller one’s neck or back.
Catching small prey
It seems logical that a game dogs love would somehow have its roots in natural dog behavior. A long time ago, our canine friends would actually hunt for their food, just like wolves. As small mammals like rabbits and stoats hide away in underground burrows, dogs would have to pull them out of there once they had the poor animal cornered, which might be the reason why contemporary dogs still love to tug on a rope.
Tearing a large carcass to pieces
While the wolves that we see today are no direct ancestors of our beloved dogs, both species still share a common ancestor. Since wolves hunt in packs, our dogs probably used to do so too, which would allow them to take down large prey. The love for pulling on a rope might date back to times when wild dogs caught big animals that they had to shred to pieces. Think of tearing a leg off a deer for example.