The myth is so pervasive because it's propagated by people with more wealth against people with less of it, and the conflict of interest prevents anyone from giving it up.

Everyone wants to feel better about themselves and the easiest way is to look down on someone who has less. Less "whatever" really, people always find something that they think makes them better, money is just the obvious choice because society slowly associated money with success. It doesn't matter if the wealth came from their parents, or luck, they can still pretend it makes them better.

I think it’s self evidently true that hard work is not equal to wealth and I don’t know how that meme became a thing.

You can exert extreme effort in unproductive directions and provide marginal, even extremely negative, value.

You can work extremely hard, all day every day, and accomplish nothing.

Gulags aren’t known for their wealth or value generation. They’re known for their labor input.