The answer is that he had to be a near kinsman, more or less meaning the closest eligible relative, as well as needing to be willing and able. Do you like my next picture? I was hoping you’d appreciate my consideration for your feelings.
Now, mankind had lost everything to sin. We needed someone to redeem us. Someone became a human being so that He would be our near kinsman. He was very willing, and because He was sinless, He was the only one able to redeem us. Who was and is THE Kinsman-Redeemer?