Self employed would pay this 13% plus both sides of Social Security for another 13+% on top of state income tax and Federal tax. Sounds like the self employed have the choice to go out of business or jump their prices for their labor, as well as other employers adjusting.
I think I’d relocate.
Under this system a single, self-employed person in VT whose business netted $90K would pay $44.6K in taxes. Hardly worth it to create those new jobs for others.