> in order to optimise your taxes, you have to be quite wealthy to begin with (hiring a tax guy, etc.)

Another way of thinking about this is that the wealthy person is incentivized to invest their wealth directly into higher-risk, economy-boosting activities like starting businesses that (if successful) create jobs that then pay income taxes. Ideally tax revenue is generated from this incentive. The wealthy person could just buy gold bars and create no jobs that generate income tax, but they don't get as good a tax deal on that.