Massive lying and resume inflation? Performance anxiety leading to bombing interviews? Maybe the roles they were in didn’t actually require as much programming, or deep understanding of programming as people would expect?
It could just be that a massive amount of work in the software industry is really code monkey work. “Gluing together APIs.” Refactoring existing code. All things that can be accomplished by referring to Stack Overflow copypasta or the existing codebase itself without requiring the coder to have any deep independent understanding of the code or the language they claim to know.
And, if that gets the job done- how high should engineering standards even be if so much of the work is menial? Either able to be outsourced, or one day Autopiloted away?