Correct, that's the point.

> the more you save, the bigger your tax gets, while your income stays the same.

Only if you're a completely useless investor. Most people's income increases as their wealth increases. That's part of the problem. Especially the "r > g" question: are you growing the pie or simply sitting on a larger share?

On the other hand, this can and should be irrelevant to the average family. Start the wealth tax at $1m, say.