|Towards more picturesque speech™
Why to the benefit of? Because it is the verbal construction that provides enough diversion to obscure the fact that this is a statement of not jsut the bleeding obvious, but the necessarily true. A contract creates rights and obligations in and of itself; there is no need to further inure them to anyone. The inheritance of a right between a dying, or merging, or assigning counterpasrty is likewise an operation of some other legal process (perhaps a novation, merger or the laws surrounding probate and succession) and not, principally contract (except where it bars assignment). I have a right. Thus, inuring is purest flannel. If you are a party to a contract your counterparty's obligations are legally binding. That’s all you need to know. Chicken licken, relax: the sky will not fall on your head if you don't say they “inure” to you. Or, for that matter, to you successors and assigns.