I share your skepticism about the author’s outrageous claims, but I can give details on how self employment has given my family more flexibility with taxes and benefits.
We set up a solo 401k let us max out tax-deductible contributions on the employer side as well as the employee side, which is great for our early retirement plans because we have a much higher limit than if we were contributing to a typical employer’s plan. We are also able to work part-time without forfeiting our ability to participate in the plan, unlike a lot of employers which only offer retirement accounts to full-time employees.
We also realized that at least in our state, the income threshold for qualifying for state-sponsored health care is based on adjusted gross income. Our ability to contribute so much of our income to pre-tax retirement accounts means that we can qualify for health care despite earning significantly more, as long as we’re putting all the extra into the retirement accounts. We have to keep our spending low to be able to save that much, but that’s in line with our FIRE goals anyway.