I don’t know why assume that in every country in the world that is free. In my European country until 15 years ago or so you had to hire someone to do your taxes for you, and currently the free method only works for the most simple tax filing. In fact what you get is called a “draft” of your tax filings because you’re supposed to make sure it’s okay, and it’s your responsibility if you miss something or if the draft is wrong.
And obviously the draft usually assumes that you will have to pay more tax, since there’s a perverse incentive given it’s the government who fills it for you.