[penr0se]

That makes sense, but I would expect this paradox to vanish (or at least get weaker) as you go higher in the hierarchy of technical positions (i.e. from junior to lead, to senior, to principal etc.). I would expect the workplace to somehow naturally get rid of the incompetent people, so that after a certain point you're only left with [qualified, competent] and [unqualified, competent]

[toast0]

One of the best ways to get rid of someone is to recommend them highly to an open position somewhere else. Sometimes a higher level position, or management.

[thomastjeffery]

When a software engineer gets promoted to a senior role, their responsibility changes to impact a broader timescale. It's entirely possible that promotion is the very thing that masks their incompetence.

For example, a junior developer is expected to manage implementation details, while a senior developer is expected to manage business logic. Incompetently designed business logic is noticed later, and can often be blamed on trivial implementation failure.

[oasisaimlessly]

See also: The Peter principle https://en.wikipedia.org/wiki/Peter_principle