[JSavageOne]

The incentive is in the reward you get for performing well.

Also I don't think it's necessary that a job guarantee make an employee immune from being fired. I'd imagine a job guarantee would have all kinds of jobs ranging from relatively simple (eg. cleaning) to more complex (eg. science). If you're in a more demanding department and underperforming, you could get fired and have to apply to another job in another department.

For example, the military is sort of like a job guarantee in the sense that anyone meeting the physical bar is effectively hired. But any military member can get discharged.