I generally agree with a flat tax rate, but how do you think about it in terms of economic growth? If someone earning $40,000 a year is working full time, is paying 50% of their wage on housing, and the rest on living expenses - then paying 30% tax might prevent them for also taking on education costs to study for qualifications for a new job. Would you be open for someone in that situation paying less than the flat rate so they could eventually earn more and add more valuable economic activity later?
You are looking at it from the perspective of current situation. The average fortune 500 company pays around 11% tax, with some paying zero. This is on their already lower taxes compared to the people they employ. Close the loopholes. Make it so taxes are paid in the places the income is earned, not in some tax haven or country with lower tax incentives. Taxes on passive earnings shouldn't be lower than taxes on active work performed, should it? Inject the increased revenue into lowering ridiculous education costs, reducing the cost of quality foods, and increasing taxes on obvious luxury goods. Provide support where necessary.
Ah, you're right... I was thinking about it from the perspective of the tax limiting an individuals means for wealth mobility, instead of thinking about the tax from companies removing the friction. That works for me.