How can being too good at your job keep you from getting promoted? how can you avoid this issue?

Being to good at your job can keep you from getting promoted by them not wanting to lose you in that department.
You can avoid this issue if you are good at what you do but could do better in another department or station.

If you are too good at your job your higher ups may want to keep you in the position you are currently in because you obviously do it exceptionally well. You can avoid this issue by doing your job, but not overdoing it. Yes, you can go above and beyond every now and then, but be careful not to end up in a rut where you'll be working the same job for years.

The will be a : great britain wanted french gold mines