After a few decades of working in a variety of positions, I've come to the conclusion that the "Peter Principle" is cute, pithy aphorism but not reflective of reality. The crux is that "competence" and promotion is not a one dimensional ladder where each promotion requires you to simply be more competent than in your previous position. While this is sometimes true, just as often, promotion means that you need to exercise different skills. Which you may or may not be able to do well (or learn rapidly enough).

For example, getting promoted to "senior developer" may mean higher expectations than just "developer". But you may also be expected to architect parts of systems, mentor more junior staff, provide guidance etc. Even more starkly, if you get promoted to something like "team lead" or a more managerial/executive level position, your need to be focus more on prioritization, managing people, etc. Very different skills than writing code.

Further down, the author wrote:

"The transformation into a syndrome shifted the experience of being impostered by a patriarchal, white supremacist society into a medicalized disorder, something for which the impostered person must be treated. That’s a neat trick: to shift the locus of treatment to the mistreated person, rather than the system that caused her harm."

At which point, I have to admit, I said "WTF?" in my head. One could just as easily say the transformation into "syndrome" is rooted in a society that has shifted from focusing on actions and accountability to one that focuses ever more on inner-feelings as what is important.

Also, in my experience, people are already doing the thing before they get promoted to it. There's a continuum of skills. From developer to senior developer, you're not just one day developer with your heads down or writing code and the next day you're only architecting and mentoring others. You start out as a developer and if you're good at mentoring, people start to seek you out for questions and soon you become the mentor and you get promoted because you're already doing it in a small level and they want to reward you and encourage that. Similar for architecting the system, if you're a low level developer and thinking about architecture things you're already doing that work and you're reward it for it by giving more responsibility to do it more.

However, one thing to note is the senior level positions, the higher you go, the more you're a people person. A low-level developer can think about architecture all day long, but because they never talk to anyone about the ideas, discuss if it's really good or bad, understand the pros and cons of the ideas that others have, they're going to remain a low-level developer. This is why senior developers move in and out of management very often in a lot of companies. The jobs are not nearly as different as people would imagine. In both cases, you're more a people person than a technical person. It's just that as the senior developer, you still keep that developer hat on and write code, whereas as a manager, you're only a people person.

> The crux is that "competence" and promotion is not a one dimensional ladder where each promotion requires you to simply be more competent than in your previous position.

This doesn't contradict the Peter Principle, which doesn't imply you're increasing competence on a single axis.

In its most bare form, the principle states that people get promoted until they get stuck at a role in which they cannot adapt and do a bad job at. It never states it's a single dimension of competence or incremental over their last role.