Is there really job security in banking

We have heard the horror stories in hours and analysts being treated as disposable, but for some reason this job is seen as secure. I do not know how, if you are constantly sleep deprived, you can produce consistently good work, which brings the question: how often do people get fired? And assuming one goes two days without sleep and gets fired for some reason, is that just the nature of the job? Let us leave the effects of AI out of this one