You need the stretch of strap to give that extra pull when trying to unstick a truck and trailer in the sand. If you hang a blanket or jacket over the strap it controls the rebound if it breaks. Chains don't just "fall to the ground" they can whip unpredictably as well. If the chain broke the broken link is going to be flying like a bullet from a gun. Chains usually have load limits way below recovery straps. The strap I linked to in my post is rated at 24,000 lbs.
Best practice is to not use anything that can become a projectile, so a strap with loops only, no hooks, and looped onto a part of the truck that can't break off, so if the strap breaks it's just the strap coming at you, it's not launching a broken tow hook or other metal part.
I know guys that use chains and I am not a fan of them. Bottom line both are dangerous.