So many things are made in other countries these days, which means that when taxes are cut, the extra money is largely spent on economic activity elsewhere. Or else it is pocketed.
As a former small businessman/job creator, I can say two things about tax cuts and their effect on the economy. First, one has to have large profits, before a tax cut has any real effect on operating practices, and second, the effect is more likely to be a reduction in debt, which reduces interest payments on lines of credit, and unlikely to be used to reinvest in capital outlay, or new hiring.
The cash value of the tax cut goes straight to a bank's bottom line, who is also benefiting from the tax cut.
There is no investment which creates new wealth, which produces taxable income.
The problem with all of these trickle down get government off the people's backs tax reform plans is that no one ever steps up and says that it means a reduction in the standard of living for most of the tax payers. If State government got out of the business of things like healthcare, infrastructure, and schools, and let local government do whatever they could afford, tax rates could revert to pre Spanish American War levels.
Governments were instituted because it was many years ago that we realized, the wealthy will pay to educate their own children, but not anyone else's children. The same goes for all the other things government does in a first world country.