How do I deal with being treated as less than I am at work?

You know your worth, and you are tired of a system that keeps acting like you are filling a gap until the real thing shows up. That resentment is not bitterness. It is the honest response of someone whose skill is not being met with respect. You cannot make the system see you clearly by working harder inside its blind spots. What you can control is where you spend your strength. Some of that energy is being burned proving a point that the people above you may never concede. Ask which battles are actually moving your standing, and which are just wearing you down. Start by finding one person or place that already values what you do, and pour more of yourself there. Recognition rarely comes from the room that has decided not to give it. It comes from building a reputation elsewhere until the old room has to catch up. Let your work speak where it will actually be heard.