Several countries have already figured this out, ot isn’t rocket surgery. The government has a pretty good idea what you owe, and send you a bill. If you want to take another route, you’re free to submit your own taxes, but the vast majority don’t need to do anything like that. There’s no reason we couldn’t use the same system, if it assumes standard deduction that would cover the vast majority of people. Anyone who wants to itemize would be free to, it just wouldn’t be automatic, so essentially, nothing would change for them. Well, almost nothing, the difference is if they take too long they have a safety net standard deduction already filed and done I guess.