And we know now that the ultra-rich folks tend to take the money,windfall from lower tax, and hide it in Virgin-Island, Panama,Cayman Island and other offshore tax havens.
https://en.wikipedia.org/wiki/Trickle-down_economics#Critici...
"Mr. David Stockman has said that supply-side economics was merely a cover for the trickle-down approach to economic policy—what an older and less elegant generation called the horse-and-sparrow theory: 'If you feed the horse enough oats, some will pass through to the road for the sparrows.'"
It feels more honest that way.
It's a relatively well known fact that eg it doesn't really matter too much whether officially the employer or the employee is required to pay the employees income tax---the money comes out of the same pot.
Similar things happen for other taxes. Eg VAT in European countries seems to be paid for by the shops, but it wouldn't make a difference (apart from convenience in collection) if you'd levied it directly on the shoppers.
Any discussions about 'trickle-down economics' is incomplete without tax-incidence.