True, there are times when those in IT are expected to be broadly knowledgeable far beyond reality. But I also saw a number of times where some of the folks I worked with made CLAIMS of being knowledgeable far beyond reality. They were very good at expostulation and pontification but when (pardon the pun) the chips were down, they were pretty much worthless.
As far as being dismissed for lack of capability, once in my 40-plus years in IT and 11 years of management did I need to dismiss an individual due to lack of learning and adapting ability. I hired a young man directly out of his two-year community college studies where he had apparently done well. The unfortunate reality was that he did not dig in and become useful, and did not fit in well with other IT staff, instead being content to drift along and wait for specific and detailed direction.
So yes, in all sorts of IT work and other occupations, there is always the harsh reality. Sometimes you have to just walk away. We'll all experience this eventually.
The only thing worse than being an influencer
is believing one.