…if experience is at such a premium, why are there so many articles about how hard it is for older IT workers to find a job?
People don’t really absorb the lessons that their experience offers. In one sense, they haven’t so much gained experience as they have had things happen to them. They become neither knowledgeable nor jaded. They haven’t processed the ideas or compared real-world happenings with their theories of how the world works. Without this processing, experience isn’t really a great teacher or a cruel one; it is only a way to mark the passage of time.
So much for information technology.
You learn by dealing with events as they happen. Eventually you build up a stock of mental tools that mean you can deal with previously unmet situations.
This accumulated knowledge makes many aspects of work so much easier they fade into the background. This leaves plenty of spare brainpower and energy to deal with the bigger issues. There may not be a perfect correlation between experience and knowledge or wisdom, but there’s certainly a link.