Hard-earned money, – really?

Republicans keep referring to the “hard-earned” money of the rich.
Really?
It should not be so hard to realize that beyond a certain income level, it becomes
progressively easier to make more, – whether your financial base was inherited or
actually a result of your own labor, investment, or ingenuity. The incremental effort
clearly diminishes with rising income level.
Someone making a hundred million a year doesn’t work a hundred times harder
than someone making a mere million, and the million-maker doesn’t work ten times
harder than someone making a hundred grand. On the other hand, very low-income
workers often work harder than those making a more comfortable living, and usually under
far less pleasant conditions.
Also, the more you have accumulated, the more likely it is that your money works for
you, rather than sweating it yourself.
Is enough ever enough for many of those making the most, – and who also often complain the most?