You have made very insightful points, and it appears you’re another student of Frederick Bastiat (seen/unseen).
However I think pragmatism will devolve down to corn farmers directing their tax dollars to ethanol subsidies and other such shenanigans as can be deployed for selfish gains. I’m sure the bankers master this game (IMF). Consider that the 1% pay the vast burden of income taxes.
As for government spending, budgeting happens from the bottom up. In the form each of Xerographica’s agencies submit budgets every year asking for 5% more than last year , with justification for new spending. These are rolled up to the master budget and rolled up to congress with support money from the social workers labor unions, supply industry, teachers unions, etc.
Each of those groups will selfishly direct the memberships tax dollars to themselves.