Sooner or later most of us encounter a financial adviser who tells us that the average household spends about 30% on housing and 20% on food, and, while our household may not be average, it's good to think in those terms occasionally as a yardstick.
So, what should we pay in taxes? In most of the world that looks like someplace we might want to be, people pay about 50% of their income in taxes, most of them without grumbling.
It's the price we pay for good government, and good government is the reason we're not still living in mud-daub huts. Good government is not something we can afford thanks to the productivity of modern trucks- modern trucks are something we can afford because we have good government.
There's all kinds of dimensions to this, but the bottom line is that if we wish to continue living as a first-world nation, we need to pay taxes at first-world rates. It's not a hard-and-fast figure, but a yardstick for use in understanding the general proportions of the problem, and of the solution.