Earlier quoted context omitted.
This reminds me of advice I got from the VP of Eng at my first real full time tech job. This was back around late 1999 / early 2000. Peak of the dot com era. He told me what most people think of as job security is totally wrong. If you're the only person who knows something, you become a liability. But if you're constantly teaching and sharing that knowledge you become incredibly valuable to the organization. That's…
> If you're the only person who knows something, you become a liability. Sorry, this is just wrong. You are a liability if someone thinks about you that way. Fortunately, not that many people are like that. In Contrary, if you are the only one to know something then you are regarded very highly and almost untouchable.
If you guard the knowledge to the core application for how the company makes it's money, you're not going anywhere.
If you guard the knowledge to a component used in that core application, which while it's problematic to replace could be swapped out with a lot of effort, you are going to be walking a tightrope. As soon as it becomes more beneficial to replace that component than keep dealing with the problem of it being hard to deal with (because if it wasn't your knowledge would have little value), you're faced with the fact that a large chunk of your value to the company has just been obsoleted with it.
So when taking the hoarding info approach, just how irreplaceable is the thing you're guarding knowledge of? Often it's far more replaceable than people think, and often becomes more so as people hoard knowledge of how to deal with it. Unless you're that guy that's on call 24/7 to immediately deal with a problem, the fact that it all relies on you which is unsustainable will eventually come to light.