Earlier quoted context omitted.
In the USA, any non-shady organization will send you a 1099- report of how much income you generated. You're supposed to submit that form when you do your taxes, which is kind of dumb, because a copy of the 1099 was already sent to the IRS. USA tax filing is not efficient for reasons... gives Intuit the stink eye
But the IRS isn't aware of what deductions you have and what credits you qualify for until you tell them. This completely changes your tax liability. When you actually understand the system , it makes sense why it is the way it is.
Countries like Estonia prefill the tax filing and they say somewhere above 90% of people don't need to make any changes when they file. Most people file within the first day and get their rebate within less than a week. If you had no significant changes (eg opened foreign bank accounts or sjmjlsr) you likely have no need to change anything. There's little fraud possible as data gathered is good and even less mistakes are possible. No one spends a day on their taxes and few need tla tax advisor for regular filing. This is increasingly common across at least Europe but sadly in few countries does it reach such sophistication yet.
Are you sure the US system works that well?