The answer to the question, "Is changing routines a good idea?," depends on one's goals. Are you asking if one can still make progress whilst never switching up anything except volume and weight? Sure, one can make gains, especially of the strength kind (but also physique). One SURELY must also be altering one's diet to make changes, but also I believe that changing up routines is also beneficial (especially when used in conjunction with diet changes).
This article plays it a little hard on the safe side, but if that's what you are going for...