Maybe I'm conflating issues here, but the IRS, like most 1st world tax agencies, already knows (in most cases) what you owe. In these other countries where this is the case, they just send you an invoice, and you don't even have to do a tax return (unless they made a mistake).

And the IRS has made efforts in the past to switch to this model. It's both good for you since it reduces hassle, and good for them since effort dealing with people making honest mistakes + effort dealing with people trying to cheat because they think the government doesn't know what they make is a huge waste, but because of lobbying from companies like Intuit, they aren't allowed to.