Couple a flat tax with repeal of the civil service laws and maybe freedom would begin to make a comeback.
Neither did the original 16th (as it was ONLY to be levied against the top 3%...IIRC [still Socialist us vs. them])
Plus, you fail to account how a flat tax would encompass ALL...not just the ‘favored’ (IE: ‘elderly’ and the ‘poor’ whom DO use services as much as the ‘middle class’...and the former more likely to BE the ‘upper class’).
Though, I’m not in disfavor of your last point ;)