> Filing taxes should be free and easy.
Or, ideally, not needed at all. In the UK having an average financial situation like a job (one that doesn’t pay megabucks, anyway), a pension, a tax-efficient savings account and a student doesn’t require any filing at all. Everything happens through payroll. If you do earn a lot or have other things that trigger the need to file it’s free and not overly onerous — certainly within the grasp of a mere mortal.
(And before someone chimes in with “how do you know the government gets the figures right?!”: because the tax code, or at least the parts that face most people, is straightforward and most people have a bog-standard default configuration that is easy to verify.)