Not really true. Those who earn more typically consume more, and those products are shipped about on those transportation systems. You pay more in property taxes because your property is larger and worth more. Etc.
The issue with that is that the poor don't have money. So a flat tax means they're dealing with starvation and homelessness and lack of medicine and such.Everyone has to pay for what the government provides; why someone should pay more for making better, more intuitive and more efficient use of that which is provided however, is not a question for which there is a satisfactory answer. No taxes for the rich? Would never suggest it. No taxes for the poor? Absolutely not. Equal tax rates for all? Good move.
The only way to get around that is if there's a guaranteed minimum income that's comfortable, and that's not the system we currently live under. Nor would that mean a reduction of taxes, it would mean an increase across the board.
The reason they tax the wealthy more is that it is not a burden on the wealthy, whereas it is on the poor. The alternative is being okay with more people starving to death and such. Civilized society doesn't see any reason why more people should starve to death so the wealthy can buy an extra sailboat.
It's not meant to be "fair". It's meant to be "equitable". The two terms are not interchangeable.To put it more simply via an analogy; two people are given a hammer by the state, both of which being exactly the same. One of those people devotes himself to mastering this tool; learning the art of carpentry and providing goods for a good deal of people who want them. The other person, sees little sense in undertaking any serious study, thinking it a pointless waste of time, and instead uses said hammer in freelance, poor quality DIY work. The state however, decides to take more from the carpenter. Not exactly fair.
If you've got a taco truck, and you've got a special on where the 500th customer eats free, if two kids come running towards the truck after your 499th, and get there at the same time, you need to figure out which is getting free food. Let's say one of the kids looks like he's starving, his clothes are torn and he's clearly struggling. The other's a fat little butterball wearing designer clothes. The "fair" way to decide would be to flip a coin. The equitable way would be to tell the fat kid to wait a sec, and give the starving kid some free food.
Because that's what decent people do. The other kid's got plenty of money; he can afford to buy his own. The entire concept of social services is that the world is NOT fair, and there needs to be a social support system to account for that. If you dislike this, you're free to pack your bags and move to a nation that doesn't have any social protection programs whatsoever. That basically eliminates every 1st world nation, and most developing nations too. Good luck with that.