I live in Norway, and every institution like banks, employers etc reports to the tax authority. My tax papers are prefilled and the only thing I have to do is check that everything is correct. Most times it is, it's just major stuff like buying a house, getting married, moving etc which might entitle you to deductions that's not automatically added. If I don't do anything, the prefilled default is filed on a certain date, so I never even have to sign in and open the tax forms if I don't want to.

If you run your own business as a sole proprietorship taxes gets more complicated, but most people don't do that.