Have you ever been so valuable in a certain position at work that it hindered your ability to move up in the company?

I’ve seen this and have experienced this in a previous role. I’ve found those who can set boundaries and say no generally move up quicker than those who agree to do everything. Not all the time, but more often than not.

I think folks my age got there a lot more than younger people. I stayed with my company for a long time but I was right at the point you describe. I stayed for other reasons but was very unhappy.

I think you have hit the nail on the head. If you are totally incompetent you are moved along, often even upwards. If very efficient in your work you are left alone.

Yep
And not be able to take time off