The income tax is by consent of the American citizenry acting through their elected representatives.
Under President Trump and Speaker Paul Ryan, severe revisions were made to the income tax laws. Speaker Ryan had the opportunity to scrap the income tax but chose not to. He knew there was no better system that would be acceptable to the citizenry.
Amendment XIII Section 1. “Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.”
Amendment V “...nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.”