I'm struggling to understand your point. Maybe I haven't had enough coffee yet.
If you make $50K, you get taxed 25% on the last $15K you made that year, or whatever. You got taxed 15% of it on the first $35K or so. The first $35K was of a higher value to you than the next $15K. As you make more money, the value of each dollar you make generally has less value to you. If you won the lottery today, the last dollar of the $15 million you won does not have as much value to you as the dollar you picked up off the street yesterday. It's most efficient for the government to tax individuals with this in mind. If you want to say it's not fair, again, I understand your point of view, I probably agree with you. It's not "fair."