I think paying your state and federal taxes in the United States should be seamless. Your employer should take the taxes out of your paycheck. At the end of the month/year, you should get a statement showing all the taxes you paid.

I recently had to update my W4 form at work for tax withholding, and what a pain in the ass to read and decipher. Add to that, and I had to do the same thing for my state taxes.

I want to point out that Congress has shot down the idea of making it easier to pay your taxes many times. I'm not sure if it is Intuit or some other entity, but paying your taxes should be easy. If you don't like the level of taxation, then work to reduce them, but paying them should be easy.

Do most Americans have to do their own taxes?

It boggles my mind that this is the case.

They do.

The UK PAYE (Pay as You Earn) system has a 1% tax gap[1] compared to 12.9% on income tax and 7% on corporation tax.

It's extraordinarily more efficient to tax at source.

[1]The percentage tax gap is the tax gap pound value as a proportion of theoretical liability, where theoretical liability is defined as the tax gap plus the amount of tax actually received.

The original purpose wasn’t to hide taxation but to effectively get more money via interest by the government getting paid sooner.

As I understand it in the US, the average taxpayer’s experience is that of annual taxes but the reality is that taxes are paid quarterly and settled on an annual basis. The self employed see this more clearly. Those in employer-employee relationships don’t see it since the employer sends the quarterly check to the various income taxing jurisdictions. Any interest made from the temporary storage of cash is probably more favorable to the employer than the government since the government spends cash faster than it arrives. The government does not escrow tax remittances in an interest generating account and then withdraw it all at year’s end.

Historically individual taxes were annual while some business taxes were quarterly. In Canada, corporate income tax is annual but sales tax remittances are quarterly. The interest is favourable to government since it reduces the amount of debt it needs to carry for a time. Admittedly it’s small now but in the 80’s it was a very big deal. I admittedly have never ran payroll taxes for a business in the US so I don’t know how that in particular works. I do however know Milton Friedman came up with the idea of withholding while working for the government early in his career and he always claimed that it was motivated by interest.