Good question and I'll need to research it more. The central goal of the tax was to spur investment in assets that generate economic activity. I really respect the Tax Foundation and the data is concerning for the value capital gains tax provides. However, there are quite a few other factors that play into GDP growth, so I am not ready to simply give up on the idea of capital gains.
An adjacent article talks about exclusions and art is one of them, so your Trump humor is unfortunately, incorrect
https://www.taxpolicycenter.org/briefing-book/how-are-capital-gains-taxed
Gains on art and collectibles are taxed at ordinary income tax rates up to a maximum rate of 28 percent.
Ironically, Reagan proposed an effective elimination of capital gains (particularly for the highest bracket), but that didn't last:
The Tax Reform Act of 1986, signed by President Ronald Reagan, raised tax rates on capital gains and lowered rates on ordinary income but set the same 28 percent top rate for both. The goal: reducing tax planning devoted to converting ordinary income to capital gains. The policy worked—briefly. Successive congresses raised the top rate on ordinary income (now 40.8 percent) and reduced the top rate on capital gains (now 23.8 percent). As the gap between the two rates grew, so did the incentives to manipulate the system. Now might be a good time to once again tax capital gains and ordinary income at the same rate, which could be higher than today’s rate on capital gains but lower than the current rate on ordinary income.
The art example is wrong, but it is still capped less than normal income, which is strange to me. It may explain why art has become a haven for money laundering? So Trump sells gold instead.... .