Careful what you wish for. If you think that any kind of flat tax that our government is likely to come up with would be better than what we now have, think again. The average taxpayer under the present income tax pays less than 10 percent. Most of the plans I've heard of, start at around 10 percent and most are much higher. The top 10 percent of taxpayers pay 70 percent of the taxes. Any flat tax will drastically shift that formula, which I'm sure would make 10 percent happy, but the other 90--not so much.
That's not to say that I would oppose a tax plan that would abolish the IRS, but I wasn't born yesterday. That tax would have to be revenue neutral (no increase in what it would cost) and even if the IRS were flushed, there has to be an agency to take its place. The state I live in has no state income tax, but it still has tax collectors.
Yes indeed the federal tax system is a mess, but what we really need to get rid of is the idiot who presently sits with his feet on the oval desk. That would be the potus, or as I like to say the pos.