How true this is depends on the field and subject matter, but surely any entity will tend to see their own specifics as basic things anyone should already know even though the field is actually much larger.
Taken to the extreme, sure. But every voluntary interaction necessarily "leaks value", being non-zero-sum.
This word "training" keeps getting used, and I think it's at the heart of this disagreement - viewing learning as a discrete top-down event as opposed to a continuous process.
GP's example is akin to an employer paying for a bachelor's degree. My comment is easiest thought of in terms of company-specific processes. For any specific 'skill', the truth lies somewhere in the middle.
Software is a bit of a rare case where most tools are highly complex, but are also freely (as-in-beer) accessible. Tool choice is heavily driven by fashion, yet fashion being foreign to our worldview we're blind to this. Is $software_package a fundamental that every college graduate should know, or basically equivalent to an in-house framework? Who knows...