Mechanical devices, like ski bindings, can deteriorate over time with wear and age which is why the manufacturers recommend that they’re tested annually.
Not only is it important to have them tested to ensure that they release correctly but it’s also important that the reading on the DIN scale really is the value that they release on.
Jon has one of only a few ski binding torque testing machines in the UK (a Wintersteiger Skitronic Plus c/w the latest wide ski clamps & the latest software release) and it only costs £30 to have your bindings checked.