I always viewed my termination as a version of the "sysadmin paradox". If a sysadmin does her job poorly, stuff breaks a lot, and she gets to save the day - she's the hero! Everyone recognizes her awesomeness. However, if she does her job well, nothing ever breaks, everything is quiet, no heroism - well, someone in management will eventually think she's useless and eliminate her position. I think that's what happened in my case. I took pride in the "quietness" of my systems, and I think someone took that as my job being unnecessary.
https://blog.devolutions.net/2017/07/sysadminotaur-61-the-sy...
> I heard from former colleagues that no one knew the admin passwords for their critical systems except me
And looks like they tried to address the fact that the entire sysadmin operation depended on them and management did nothing?
That's a lot of hostility and assumptions about some person on the internet and by the looks of it I'll make the assumption you've never worked on chaotic places where management is just shitty? I'm in the same situation at my company where I'm the only person managing our legacy CI/CD pipelines which are quite complex and nobody wants to learn it and management keeps saying they'll hire somebody as backup but they never do so I can relate to parent.