Dig, but I remember picking up in some research I did some time ago that the actual method of collecting taxes was discussed and debated by the powers that be for some time before that, with the withholding people being defeated at first until they were worn down by those who favored it by '43. Just going off the top of my head, here, but there was talk about whether it was just to collect for next year's taxes or better to bill for last year's taxes, etc., etc. I think this was the stuff you were alluding to further upstream.
But this is just the history, of course. The system we have in place now (withholdings) absolutely blows, and I think it's led to many of the issues we face currently viz-a-viz massive government spending. Just the attitude withholdings fosters is absolutely devastating. Every time I hear someone talking about the money he/she is getting BACK I want to tear out the remaining hairs on my head.
If we have to have a federal income tax, I think it should be a bill for "services rendered" that you pay out-of-pocket just like every other bill, perhaps on a quarterly basis. Two benefits, there: (1) People could stash money in an interest-bearing account until it's time to pay the piper, and (2) People will no longer be detached from the dollar amount (typically in the several thousands) they pay to the federal government. I am fully convinced once people wrap their heads around that amount, you'd see wholesale change. And that's exactly why the powers that be will never do it.
Your suspensions about withholding are well founded.
The debates show that the lawmakers understood that using withholding would make it much, much easier to impose taxes.
The lesson from the world of retail was that customers will spend more money if they can make small regular payments rather one large lump sum. And if the money can be collected before they get their hands on it it’s even easier.
I think Ronald Reagan had proposed to do away with State withholding when he was Governor, because he wanted Californians to be more aware of how much money was being taken from them in taxes.