What if never speaking up has held my career back?

For years you did not push. You did not ask for the raise, the title, the credit, the better project. Each silence felt small at the time, but they added up, and now you are looking at a career that sits below where it could have been. That is a hard thing to see clearly, and you are seeing it. Be careful how you judge the person who stayed quiet. They were probably trying to be good, humble, easy to work with, not the type who grabs. Those are not bad instincts. They were just aimed wrong, applied in places where a fair ask would have served you and no one else would have minded. The past cannot be reopened, so let it teach instead of accuse. What you can do is make the next ask. Choose one thing you want, that you have earned, and say it out loud to the person who can grant it. Just one. The compounding runs both ways. Every time you advocate from here forward, you start bending the curve back toward where it should have gone.