income taxes being a blend of all the tax rates up until his max rate.

You are incorrect about the employee not paying the full 15.3% for FICA taxes. His employer has already shown they are willing to pay an extra 7.65% for his services. Remove the tax obligation and supply and demand in the labor market moves his salary up accordingly.

I knew someone would call me out on the 15.3% FICA tax rate... That's why I threw it in there at 15.3% instead of 7.65%. If more people realized it is actually 15.3%, there would be more pushback when politicians try to raise taxes.