If only they had a dually...(Travel Trailer rollover)

Yep. In his case, he had safety chains and it kept everything together. My point being that they do, indeed, work as advertised in some cases.

Chains are there for a reason, and you can be cited for not having them. Will they work in every accident? Nope. But if they are hooked up and they break during an accident, then that citation/liability is one less thing you have to worry about.