> Why is the system still this backwards? Either plain ignorance of there being a superior alternative, or a broken political system that can't get anything done.

Neither. There is awareness of the alternatives, and the political system can get things done for it's real constituents. The problem is a malevolent political system that primarily serves a class whose interests are opposed to the mass of the citizenry, to wit, a narrow capitalist elite.

(People will point to the tax prep industry, it's lobbying, etc., and that is part of the problem; an bigger part, however, is the political faction favoring lower taxes in general for the elites that likes to maximize the perceived pain of taxes for the masses to generate support for elite-favoring tax cuts; they are adamantly opposed to procedural simplification that minimizes the pain they leverage.)