When something becomes routine for a developer, where they can predictably finish a work item without designing anything new, that task is immediately flagged in managers' minds as one that should be done by a more-junior/contractor/3rd-party/off-the-shelf solution. Almost by definition, then, good developers are relegated to only doing tasks that they are doing for the first time. The implications of this natural law are evident in the quality of the output, the predictability of the schedule, and career burn-out of people who are asked to be creative 100% of the time.