Career progression. A small department with not much chance of promotion or acceptable pay rise against others in similar roles would be the main reason.
I would never leave, I love it.
Answered - Engineering Manager (Current Employee) - Southend-on-Sea, Essex
Management (or complete lack of), gets exponentially worse the further up the chain you go. Poor salary in comparison with the real world.
Under market pay and differing benefits dependent on location
Answered - private (Current Employee) - private