You're asserting it's waste, fraud at the top (leaving bureaucracy out of this for the moment because it's a buzz word deployed by politicians to obfuscate, distract, blame-shift) which is then allegedly trickling down to the state and local levels. So let's examine a hypothetical scenario of corruption in two houses:
Let's say Sam lives in House 1; Sam handles a buttload of money on a daily basis, is wasteful and corrupt.
Albert lives across town in House 2; at a lesser magnitude Albert is in the same business as Sam, has his own scams running but legally operates as one of Sam's ancillaries in a similarly wasteful and corrupt fashion.
Now, by virtue of your argument, it should follow that when Sam gets busted, all corrupt operations at Albert's house cease because Albert's corruption hinged on the now interupted trickle-down.
Except that's not how it works because synergistic corruption takes a minimum of two participants and the removal of one party doesn't undo the corruption of the other. To the contrary, because Albert is operating as Sam's legal fundee, the only thing which changes for Albert upon Sam being stung is number of available revenue streams.
Or, to put it more succinctly, both Sam and Albert are corrupt and, while Albert legitimately does business with Sam, what happens in Albert's house, under Albert's roof is on Albert -meaning that cutting off funding from the top will not stop "the people who cannot run the system now," force them to "figure out how to do it [acquire funds]" because they already know. Rather it would simply remove one revenue stream from their reach -the alleged corruption would continue and the response to the lost stream would simply be to raise/enact new taxes to cover the gap.