Tax revenue -- that is, money coming into government treasury -- is largely predicated on economic growth, rather than tax rates.
Lowering tax rates does not necessarily reduce money coming into government. Raising tax rates does not necessarily increase money coming into government.
Life isn't that simple. Don't listen to Democrats and Republicans that want to paint you such a simplistic picture.
There is of course the Laffer Curve that suggest there is a point in taxation past which there are diminishing returns.
Research done, with the Laffer Curve in mind, strongly suggests that the optimal tax rate varies between 10% and 16%, depending on many variables largely outside the control of government regulations.
So after all this time, the old testament 'tithe' rule, which was originally
a form of voluntary fundraising for the government (the religion and the government were inseperable), continues to prove itself as the wisest course of action.