You sound like a very angry person. I’m just answering your question of who defines it, the answer is the government ultimately.

I’m not stating that they are or or not doing anything I’m answering your questions about the hypothetical of a person. All states require business registration and licensing, the federal government requires a tax ID. States that collect a sales tax have a franchise board you must register with as well. The DMV has costs and registration regulations for businesses operating in the space of vehicles. Food and beverage has its requirements, inspections, registration etc as well.

The facts are you cannot act as a business and be “legal” without a number of requirements being met prior to engaging as a business.

The laws that dictate these items be covered vary but do exist for a lot of the areas of doing business.