Stuck because he had a family to provide for and it paid pretty well. He loved the people he worked with, but it didn’t have the opportunity for growth. After becoming empty nesters he left the job this last summer. Took a pay cut, but he’s enjoying work again because of exactly what you said. It’s allowing him to keep learning and growing. His previous employer even they gave him the green light and said he could come back if it didn’t work out.
human’s need to be stretched and challenged. Unfortunately it’s human nature to avoid those things.