There are slightly different issues here: fragmentation and cost. You could have a mix of non-free and unified, or free and fragmented etc.
It's fragmented because states here in US have their own laws, taxes, etc. So do local municipalities. Some cities collect some types of taxes, some others and so on. When it comes to stuff like taxes it may be easier to think of US as the EU.
Non-free is because of lobbying by various tax prep companies. It's a large business and here in US there is thing about not wanting the US government to compete with companies. So all these parasites popped up and now are saying "you can't compete with us, it will destroy us!". They always say something how anyone can get paper forms and mail stuff in, so all the electronic stuff is not needed and is just a convenience.
It's fragmented because states here in US have their own laws, taxes, etc. So do local municipalities. Some cities collect some types of taxes, some others and so on. When it comes to stuff like taxes it may be easier to think of US as the EU.
Non-free is because of lobbying by various tax prep companies. It's a large business and here in US there is thing about not wanting the US government to compete with companies. So all these parasites popped up and now are saying "you can't compete with us, it will destroy us!". They always say something how anyone can get paper forms and mail stuff in, so all the electronic stuff is not needed and is just a convenience.