“...supply-side tax cuts like Reagan’s (and Trump’s) also distort the economy...”
Milton Freidman has said that any excuse to give a tax cut is good.
Reducing taxes keeps more money in the private sector; that is where wealth is created.
Ideally, taxes should be zero. Starting from a position of high taxes, cuts are good, but are still second-best. There will still be distortions of economic behavior because there are still taxes. Even more so with subsidies.