As far as I can be bothered to care, schemes involving having other people store your money such as tax withholdings and insurance policies exist primarily to save people from themselves and their lack of budgeting capabilities.
Most people can't budget, poor people especially so (it's among the biggest and most likely reasons why they are poor). They see money, they spend it all immediately. Saving? Investing? "roflmao" or "I can't.", they will say. The only way to address this so certain, specific, important payments are made absolutely is to literally take and keep the money out of the person's hands until the payment is made.
Most people can't budget, poor people especially so (it's among the biggest and most likely reasons why they are poor). They see money, they spend it all immediately. Saving? Investing? "roflmao" or "I can't.", they will say. The only way to address this so certain, specific, important payments are made absolutely is to literally take and keep the money out of the person's hands until the payment is made.