If you retired and start to withdraw money from a Traditional IRA, is all the money that you withdraw taxed at the lower rate possible since you make no income?

I understand that people put money into a Roth IRA because they assume that they will be in a higher tax bracket later on, but couldn't they put it in a Traditional IRA and just wait till they are retired at say 67.5 before withdrawing the money to guarantee that they are in the lowest income tax bracket when they withdraw money?