If most people had the money in hand, and had to save to pay their taxes, we'd have much lower taxes. Fewer services, true, but it would be worth it.
Interestingly, the idea of tax withholding was originated by (of all people) Milton Friedman, when he was a young research economist during WWII. The government was desperate for money to carry on the war effort.
Later, in reflecting back on it, Friedman said something to the effect of it seeming necessary at the time, but if he had the choice now, he'd do away with it.
https://fee.org/articles/wartime-origins-of-modern-income-tax-withholding/
Wartime Origins of Modern Income-Tax Withholding
Milton Friedman Did Not Foresee the Long-Term Implications of the 1943 Tax-Withholding Law
Thursday, November 1, 2007