As a percentage of GDP this is largely true (with some moderate exceptions when tax rates hit a low “sweet spot” on the Laffer Curve).
They leave a few details out but this is incredibly educational.
When the rate is raised too high, not only will there be more loopholes lobbied for, but there will also be massive non-compliance. Non-compliance can come in several forms, such as just not moving their money, storing it in gold or other assets, investing it in China, or the wealth producers simply expatriate.
Bill Whittle’s analogy about government taking a smaller piece of a larger pie is spot on.