You are not growing on the job
If there is no growth and development in your work, then it’s time to reconsider. Your job must expose you to learning opportunities and you must take advantage of them to develop yourself. In some companies, funds are set aside by employers to send their staff for training and skills development. Your employer should have a similar policy if not same. Thus, if these policies are there and you are not taking advantage of them or they are non-existent, then it’s time to walk out the door.