People bs-ing in their cvs about their actual experience is one of the factors interview process has become like this.
However, a lot of them will have real problems when switching companies and being faced with a real technical interview as they are severely lacking in technical depth. Ask them about anything deeper than a manager's understanding of the topic and they will waffle on without answering the question. "What security measures did you take in your code?" - is a good question, followed up by a more specific "how did you prevent injection attacks when you did X?" (YMMV). Usually these candidates have no clue what that even is, compared to someone who actually had to deal with the nasty bits of the job the project hoppers can't be asked to deal with.