No, the point is that we subjects get to keep more of the resources for which we work.
Any primarily agricultural state would have had trouble "supercharging growth" over that period. Also Kansas sucks, so it's perfectly possible that "tax cuts" were implemented as direct handouts to the Koch brothers, which of course I wouldn't defend. The general idea of tax cuts is fine, though. b^)
You are moving the goalposts after the experiment has failed. Before these tax reforms were passed, their advocates said over and over that the point was to supercharge growth, and that the tax cuts would surely accomplish that.
But without massive spending cuts, you need supercharged growth to offset lost revenue. The premise of Kansas-style tax policy -- which coincides in spirit with Trump's proposed tax policy -- is that you can avoid massive spending cuts by supercharging growth.
Without that premise, these tax policies would be much more difficult to push through. Because they'd have to admit massive deficit spending, or else come pre-packaged with huge cuts to popular services.
So, the end goal isn't necessarily to supercharge growth, but the promise to supercharge growth is a huge aspect of what makes these tax plans politically viable.