Being asked to rule yourself out of a job that you are interviewing for (or else deflect the question with some bullshit humblebrag) is far from an ideal gauge of self-awareness.
If you think admitting you are not perfect would "rule you out" of a job it sounds like you haven't really interacted with real humans much (i.e. no sane person thinks that someone talking about something they struggle with when specifically asked is a disqualification). If an employer decides to not offer you a job based on your answer (assuming it isn't something along the lines of "I embezzle massively from every employer"), that is unlikely to be a place you really want to work anyways, in the long run.
The problem is that any answer to the question will hurt you. It's just a question of minimizing the harm. There's also a competitive aspect to it where if you don't lie, someone else will.