I agree with the premise of the OP: Inequality like this is unsustainable.
[Economic or income] inequality like this is unsustainable.
That does not mean that the opposite of the current situation is complete economic parity - sameness or uniformity. The word "inequality" in this context is describing a matter of degree.
Seems you're tilting at windmills (or strawmen) to assume that anyone is proposing communism as the solution to the widening income gap.