They make even the simple case more complicated than it needs to be. In these other countries, most people don't need to file anything, it just works with what the state already knows. You don't have to provide a load of supplementary info to get the correct outcome. I can only guess you think this way because you've not done taxes in another country.
Just noting that in your benchmark (which we know nothing about), your "naive" data point is just 2.29x slower than hist. In their testing it was 27x slower! And it's not quite the same naive shell command, which isn't helpful.
