Do you have any sort of citation to back this up?
Capital gains tax is a thing, and in most cases that capital is taxed multiple times through its "lifecycle". The reason capital gains are taxed at a lower rate is because we want to encourage capital investment. It's what makes things. Food. Jobs.
You're also following a flawed premise (many people do this) that wealth is a finite pool, or a zero-sum game.
It isn't.
There's no upper bound to wealth creation. It's not a limited pool. It's unlimited.
Wealth is created when a person, or group of people, create a product or service that other people desire. That's it. Anyone can do it, and successful people do - through a combination of work, opportunity identification and luck.
The ideology I see behind "wealth inequality" in the U.S. typically boils down to some derivative of envy.
The solution to "wealth inequality" isn't taxation - that only has the power to destroy.
The solution is individual, different for each person, their life goals and what sorts of things are important to them, but rests in creation and innovation.
That's what's created wealth through human history, and it's what will continue to do so, if we allow it.
Taxing others and giving it away is lots of fun until you run out of people to tax, and you've managed to disincentivize and destroy what wealth remains.
Take a look at Prodrazvyorstka [1] to see how that works out.
[1] https://en.wikipedia.org/wiki/Prodrazvyorstka