Here in Portugal, tax comes pre calculated from the government on a free web application. It works very well!
I just need to do very small adjustments every year before deliver the taxes.
If taxes were filed automatically, honestly, I'd pay no attention at all to them, but having to sit once a year an actually look at the amount I paid, does get me to think about taxes and what they go towards, at least a little.
Also, republics are “anti-tax” in word and pro-tax in practice, as is the American way. When it comes to particularly republicans, anti-tax is code for removing social safety nets. They want taxes if it pays them, or pays the right contractors, or funds the military etc but when those tax dollars could go to social welfare they suddenly think it’s time to trim the fat.