That’s not an unfairness of tax, that is an issue with the distribution of income. If only one person in the US had money, then that person would pay 100% of the taxes — and guess what, that part would not be unfair. What would be unfair is that one person would still have all the money.

If you want more people to pay more taxes, then what needs to be done is simple: make sure that they have the income on which they can pay tax.