I don't change up my routines much at all. Not only that, but changing up exercises every time you lift would make it near impossible to track progress. Everyone is not the same and if you are increasing the weight used as well as increasing your form and function regularly, "plateauing" shouldn't be happening to you that much to warrant changing that often for no reason.
You shouldn't even approach this as if you are expecting a plateau to occur. I have gone years doing the same routine, making progress, without changing a thing but the weight used.
I think beginners can benefit from trying different training routines if for no other reason than to allow you to find what works best for you. I have never agreed with changing the entire routine every few weeks to avoid an unknown plateau that hasn't occured.
Not only that, but if your gains stop, why move to changing your routine around before paying attention to your food intake and making adjustments there first?