There is just something mentally wrong when you just live your entire life under the notion of "this person has it better than me, therefore they have to pay more than me!" It is jealousy to the core and downright pathetic that you can't accept the fact that someone made more money than you, but for some reason they should pay a higher percentage than you. It's yet another form of keeping up with the Jones'.
Once again, if it's all for the betterment of mankind, why aren't you throwing your money up? It's because you're full of shit as far as caring for anyone or anything. Just admit it.
First, just because you make more money than someone else doesn't always mean you pay a higher percentage of your income, or even a higher total amount, than someone who makes less.
Second, society gets to decide tax rates, and how much individuals and corporations pay in taxes. If you don't like it, go live in International Waters, or Somalia.
Third, the richest people on the planet have much more incentive for government fiat currency to maintain value than someone with no money. And they also have much more incentive for the current government to continue existing to back contracts, and real property holdings. If the dollar disappeared along with federal and state governments tomorrow, all your bank accounts become worthless, and all your real property goes to whomever holds it at the moment.
Societies create taxes to pay for particular entitlements that the society thinks are just. After a long enough time, those entitlements become rights.
You can hem and haw about taxes and how it's stealing, but that's what you get when you agree to live in that society. You can attempt to change it, or you can move elsewhere.