Namely, taxing reduces whatever that is taxed. Taxing work makes work less desirable, and sometimes not worth to be done at all. Taxes should target things that are unnecessary or harming.
Thus, income shouldn't be taxed at all. Conversely, consumption should be taxed with a VAT roughly equal to the lost income tax. Food could certainly be taxed less than cars but the general rule should be that you're taxed for consuming. Because income wouldn't be taxed, people's purchasing power would increase but taxing the consumption would make them think twice where they spend their money. Consider that this is the opposite of the current situation: people are all pre-taxed (=license to consume) and items and products are so cheap they can get spent money on and ultimately discarded without anyone blinking an eye.