There's a massive difference between being perpetually employed and being fired for no reason at a job you've already demonstrated your ability at.

>being fired for no reason at a job you've already demonstrated your ability at

???

Curious to learn more about how would one ethically justify that?

No one owes nothing to another (aside from what's protected by human rights).

You owe everything to other people. What do we owe to each other is literally a joke question in things like The Good Place.