That's a gross oversimplification and thus very misleading. While your marginal tax rate on taxable income (not gross income) might be close to 50%, if you are married filing joint, a homeowner, and have children, you are not paying anywhere near 50% effective tax rate[0] on your total income, due to deductions and exemptions, credits, tax-deferred retirement contributions, tax-free health insurance, and progressive tax brackets.
[0] "effective tax rate" does not have a universally agreed single definition, but the statement holds for most reasonable definitions.