This reminds me of how incredibly good TurboTax is at UI, and if US and state governments were to invest in UI we wouldn't have to pay $100 a year just to do our taxes.
You are right. The UX for the Swedish tax filing is sub-optimal, the language is not simple and calculations are unnecessarily complex.
The main reasons are that the tax form comes prefilled, most people don't have to do any adjustments and can just sign it and hand it in. If I understand the US correctly TurboTax does a lot of lobbying against this for obvious reasons.
On top of that filing taxes can be done completely online and when you do have questions the Swedish tax agency is actually one of the most helpful and professional service that I have encountered.
Don't get too excited. Filing your taxes online in the UK is also still largely horrid, and often seems to require either starting afresh (the equivalent of "turn it on and off again") because some unknown error is reported on submission, or just phoning HMRC to talk to someone.
Whether this is because GDS haven't got their teeth into HMRC yet I don't know, but not everything over here is as shiny as some would have you believe.
Actually 'Making Tax Digital' means eventually the manual tax submission will go away. They're pushing all tax returns to be completed via API from accounting software.
Your taxes are probably more complex than mine, but to counter this with an anecdote: I've been using Self-Assessment Online for years and never had an issue with it.
