Even with a bracket system, your effective tax rate will asymptotically approach the percentage of the highest bracket as you make more and more money. Given "centre," I assume this person doesn't live in the US, and many places have higher tax brackets than the US does, including some well in excess of 50%. Also they may not have a federal vs. local distinction, etc., etc.
"The Personal Income Tax Rate in Sweden stands at 57.10 percent. Personal Income Tax Rate in Sweden averaged 56.31 percent from 1995 until 2016, reaching an all time high of 61.40 percent in 1996 and a record low of 51.50 percent in 2000."
Effective federal plus effective state plus payroll plus effective local (income plus property) can approach 50% in the US. Average sales tax paid on post-tax income to state and local can push it over. But yes, only a fraction of it is municipal.
No one pays 50% of their income as tax. That is not how tax brackets work.
Furthermore, the overwhelming majority of income tax goes to the federal government.