My view is different: the number of people who are willing to truly do evening this post recommends is just small. But those who are willing to pay the cost of success have a real chance of getting it. It's just that most people likely conclude that success is not truly worth it.
It’s interesting that the GP says ‘success’ and you’ve said ‘wealth’. One of those Freudian slips that belies true intention. More often than not, wealth follows success, not the other way around. But to be 100% clear, success and wealth are not one and the same.