Sorry, but poor people aren't running our country, have never run our country, did not create our current system of taxation, and probably will never create a system of taxation.
Rich people created this.
And they did so quite cleverly, so that they could point at the raw numbers for you and scream "SEE, WE'RE PAYING MORE!"
Which is funny because if there was a flat tax, of course they'd pay more money in taxes.
But this progressive tax system was created because wealthy people know they can afford to hire entire law offices and tax accountants to itemize their entire lives to reduce their taxable income to lower than that of poor people.
Did you know in 2018, billionaires paid a lower effective tax rate than the middle class? Their bracket may be written as higher, but through loopholes, they actually paid a smaller % of income of taxes than did the middle class.
Then finally, the burden of taxes is what is most important here. A guy making 1.6m a year will pay about 400k in taxes should he not hire an accountant, tax lawyer, build shell companies to hide money, etc. If the millionaire just paid full tax on each of his brackets (rich people still pay the same % within each bracket as the rest of us do - they're only taxed at the higher rates on income that falls within that bracket).
So 1.6m becomes 1.2m. Is that person now unable to feed his children? House them? Does that person then worry about an unexpected flat tire? Hospital bill? Of course not.
But the person paying 7% of their income in taxes, who has no accountant, who has no shell company to hide money in -- do you think the additional 4.5k of the 60k they might have made doesn't hurt them?
Of course it does.
Again, this tax system was created by, and for, rich people. It's something they can point at and say "look at the big, bad, tax man taking all my hard-earned (and inherited) money!" while omitting the fact that they never actually pay that higher % in taxes because they spend thousands to save, and hide, 10s of thousands, 100s of thousands, and in some cases millions so they never actually pay tax on it.
It's like a programmer that builds a back door into a piece of software so he can come back later and exploit it without anyone knowing.