managed to fully automate their job and hadn't told anyone about it
This guy deserved the boot. In IT, you're supposed to automate as much of your job as is feasible, because you understand that computers are there to do work whenever they can instead of people, and it applies as much to your own work as well as the work of your customers who are paying you to produce systems that do the same for them.
Once you've automated your tasks, that frees up time to do something else that's useful instead, and you either think of something new, or let your boss know and do whatever new thing they ask of you. That's called increasing productivity, and it's how companies succeed, and how you advance in you career. Thinking you can use the time that you've saved to play video games instead is a sign that you just don't care about the success of the company paying your salary that much, so why should any sensible company keep paying them?
On the other hand, if the company lets you get away with doing little, and don't give you new work because they just want you there for when things go wrong, learn lots of new stuff, and use it to get a better job that pays more.
Biting the hand that feeds IT
