Pay or being capped as the junior in other peoples eyes.

In my first dev job, which was a fantastic job, some gatekeepers wouldn't give up access or tasks that I was better suited for.

I was always going to be a bit younger, always the junior guy on the team, despite the fact I had relevant education and, in my opinion, was probably better at the job.

Eventually I left and they were upset, but I didn't like being held back. Not everyone is like that though.

Nowadays I build and run teams. I don't do any real technical work unless I need to show a junior a working example on how to do it. I'd rather watch them learn and grow.